BULLETIN
OF
THE UNIVERSITY OF TEXAS
NO. 164
FOUR TJMES A MONTH
SCIENTIFIC SERIES NO. 16 DECEMBER 22, 1910
THE AUSTIN DAM
T. U. TAYLOR, M.C.E.
Professor of Civil Engineering,
The University of Texas
PUBLISHED BY
THE UNIVERSITY OF TEXAS
AUSTIN, TEXAS
Entered as second-class mail matter at the postoffice at Austin, Texas
Cultivated mind is the guardian
genius of democracy. . . . It is
the only dictator that freemen ac¬
knowledge and the only security that
freemen desire.
President Mirabeau B. Lamar.
ACKNOWLEDGEMENTS.
This Bulletin is, in a large measure, a reprint of Water Sup¬
ply Paper Number 40 issued by the U. S. Geological Survey, early
in 1901. The former paper was prepared by the writer for the
Geological Survey just after the failure of the Austin Dam and
it contained very little hydrographic data for the very adequate
reason that practically none had been obtained by the city.
The original issue of five thousand copies was exhausted in a
few months. Since the failure of the dam the writer has kept
rather close records upon the river at Austin and other points
and these records are now published as a whole for the first time.
Some of the measurements of the river were taken while I was
acting as District Engineer for the Water Resources Branch of
the U. S. Geological Survey, while others were taken as a pri¬
vate individual.
The U. S. Geological Survey has kindly furnished nearly all
the figures and plates that appeal' in this Bulletin.
T. IT. Taylor,
November 1, 1910.
A. View of Dam and Power House from West.
B. View of Completed Dam from East.
THE AUSTIN DAM
By T. U. TAYLOR
INTRODUCTION
Austin, the capital city of the State of Texas, is situated on
the Colorado River, about two hundred miles from its month at
the Gulf of Mexico. The drainage area of this river above the
city is 37,000 square miles. The position of the City of Austin
with relation to the watershed is shown in Fig'. 1. This
watershed extends from relatively humid regions in the vicinity
-of Austin westerly into the sub-humid or semi-arid Staked
i'hiins. From 1856 to 1881 and from 1885 to 1910, inclusive,
a period of fifty-two years, the rainfall at Austin averaged
• >2.27 inches, as is shown by the table on page 83. The rainfall
over the entire watershed may be assumed to be about two-thirds
of this, or approximately 20 inches annually.
A "water power was created on the Colorado River a
short distance above the City of Austin, as related in the fol¬
lowing pages. After the dam was completed the project was
found to be only partially successful, as the amount of water
in the Colorado River fell far short of original predictions.
There was at the inception a lack of hvdrographic knowledge,
especially in regard to the minimum How of the river; and other
information, now known to be vital to the proper location of the
dam, was not obtained. Finally during the great flood of April
7. 1900, the dam was destroyed, with loss of life and property.
From measurements taken in March. 1890, it was concluded
that the minimum flow of the Colorado River was 1000 cubic
feet per second. Upon this basis and upon the assumption that
this minimum flow would be held back nights and Sundays and
utilized only sixty hours a week, it was concluded that the flow
over the Austin Dam would develop more than 14,000 horse¬
power. The city demands were placed at 2000 horsepower, and
it was the intention to sell to manufacturers the surplus of 12.-
000 horsepower.
6
Bulletin of the University of Texas
On May 28, 1896, while power was being furnished for pump¬
ing, for city lighting, and for city motors, the level of Lake
.McDonald sank below the crest of the dam and remained be¬
low until -Inly 6, reaching its minimum (5.7 feet below the crest)
on July 1. It was also below the crest from August 6 to Au¬
gust 25, and from September 10 to September 22. This condition
was sufficient evidence that the minimum How could not even
furnish 900 horsepower, while 5227 horsepower had been counted
upon. It was apparent that much of the inflow was lost by
evaporation, the area exposed to evaporation being 3 square
miles and the low level occurring during the hottest part of the
summer.
Notwithstanding this evidence that the river could not, dur¬
ing certain seasons, supply power to meet the existing demands
for water, lights, and motors, early in 1897 the Rapid Transit
Railway Company and the Dam and Suburban Railway were
added to the list of power consumers. After that the energy
developed by the waterpower was utilized: (1) in pumping
water; (2) in furnishing light to the city and citizens; (3) in
running the Rapid Transit Railway; (4) in running the Dam
and Suburban Railway; and (5) in running the motors for
various users of power in the city—such as planers, printing
presses, etc. To supply all of these demands required a total
average of 1000 horsepower.
r
FIGURE 1
Watershed of tlie Colorado River.
The Austin Dam
7
On July 4, 1897, the water again dropped below the crest of
the dam, but it flowed over again on July 17. It was also below
a few days in August, October and November, and the whole
of December. On January 1, 1898, the water was 2.3 feet below
the crest, and it did not again flow over until January 13. The
lake level was below the crest part of the months of August and
September, and it again dropped below on October 10. and con¬
tinued below until April 20, 1899, reaching a depth of 10.68
feet below the crest on March 29. From March 15 to April 17,
it was more than ten feet below the crest. It again dropped
below the crest on August 9, and remained below until October
29, reaching a minimum of 10.45 feet below crest on October
3. Thus during the year of 1899 the water was below the crest
of the dam one hundred and ninety-one days, during seventy
of which the lake level was more than ten feet below the crest,-
and during one hundred and sixty-seven days it was more than
five feet below.
The evidence was abundant and unmistakable that the flow
was not sufficient to carry the city water supply, the street light¬
ing, the street car systems, and the motors used in the city. Early
in 1899, measurements were made at the head of the lake, at
Marble Falls, at the forebay, at the tailrace, and at the station
below the railroad bridge. The measurements showed conclu¬
sively that the minimum flow was less than 200 second feet.
One second foot, with the assumed effective head of 57.5 feet
and a machinery efficiency of 80 per cent, would develop 5.227
horsepower, showing that an average minimum flow of 192 second
feet would be required to produce 1000 horsepower, not taking
into account evaporation and the leaks through the head gate
masonry ("spring"), which would increase the amount. Again,
when the lake level fell, more water would be required to develop
the same power. When the level was 10 feet below the top,
one second foot would develop only 4.3 horsepower; aud it
is highly probable that the efficiency of the machinery was not
as high as 80 per cent.
The result of the enterprise proved disappointing to a large
proportion of tin1 citizens. It is true that such a condition had
long been vaguely suspected by the people, but there were not
sufficient data at hand to make the results certain. The water-
8
Bulletin of the University of Texas
shed and the rainfall had been ascertained with some accuracy,
but the keynote of the whole project, the biggest and controlling
factor, namely, the minimum flow of the river, had been ovesesti-
mated. The feasibility of the enterprise had been demonstrated
more than ten years before, and during the interval accurate and
reliable data could have been obtained, and the minimum flow
accurately ascertained. Gauge-heights, rating table, and flow
curves could then have been obtained for one-tenth of one per
cent of the outlay for the construction of the dam. It was thus
found that the minimum flow could be relied upon to furnish
water and lights for the citizens and very little more. Fortu¬
nately for the city, there was all during these years a private
water company, whose plant was operated by steam, supplying
water and lights to the citizens.
The history of the Austin dam is unique in one respect, and
that is the number of engineers connected with it. Early in
1892, Mr. Joseph P. Frizell resigned, it is asserted, by reason
of the fact that he was hampered in his work by the city authori¬
ties. Other engineers resigned for similar causes, and at one
time a contractor in charge was ordered to follow the instruc¬
tions of a city official who was not an engineer. This peculiar
method of conducting a great public work called forth severe
criticisms from engineering journals. The failure of the dam
to meet expectations and its failure structurally were due then
to the following causes:
(1) The lack of hydrograpliic knowledge, causing (a) an
overestimate of the minimum flow, and (b) an underestimate
of the effect of evaporation.
(2) 1 he hampering of the engineers of construction.
(3) The ignoring of "■eolo^ic formation.
PRELIMINARY PROJECTS.
Texas became an independent Republic in 1836. and a few
years later a commission wras appointed to consider the question
ol locating the capital. In its report reference was made to the
possibility of developing the waterpower of the Colorado River
at Austin. Nothing was done, however, until 1871, when Mayor
Glenn had surveys made by the City Engineer. It was the plan
at thai time to convey the waters of the Colorado, by a canal.
The Austin Darn
y
from a point near Mount Bonnell, to Shoal Creek, for city and
manufacturing purposes. In 1873 a charter was granted to
certain parties, some of whom are still living, to erect a dam
across the Colorado, but it was allowed to lapse by limitation.
The drought of 1S77 called the attention of the public to the
possibilities of irrigating the lands on the Colorado River below
Austin by means of a dam erected near the city. During Gov.
Roberts' administration (1879-1883) estimates of the cost of
erecting a dam across the Colorado River at Bull Creek were made
with a view to lighting the public buildings. In 1888 the Board of
Trade had surveys made for the purpose of determining the
feasibility of damming the river, and during the year 1889 the
subject was kept before the public by frequent communications
in the newspapers.
In the latter part of 1889, the contest for mayor was largely
fought on the issue of building a dam across the Colorado River.
The result of the election foreshadowed early action in regard
to the enterprise. In February, 1890, the city council em¬
ployed Mr. J. P. Frizell to make a report on the proposed dam
and the necessary adjuncts. The report was submitted March
26, 1890, and so completely does it discuss the whole problem
that the portion which refers to the project in general and the
part which deals more particularlly with the dam, the water-
power, and the estimated total cost are here quoted, as fol¬
lows:
"The city, is at present supplied by a water company, upon
what is termed as the Holly system; that is. without the use of
a reservoir, the pressure in the pipes being maintained by the
action of the pumps, which are operated by steam, and increased
by an automatic device upon the occurrence of fires. The com¬
pany also furnishes power for the electric light system of the
city. I have not been able to obtain very complete information
in regard to the extent and size of the present system of pipes.
From what I can learn I judge that the city is rapidly outgrow¬
ing the capacity of the pipes; that by the reason of their small
size, a great and increasing burden is laid upon the pumps to
maintain pressure sufficient for domestic service in remote parts
of the system. A large part of the power of the pumps is con¬
sumed in the friction of the water in passing through the pipes;
10 Bulletin of the University of Texas
and as the city extends and increases, the protection against
tire is becoming more and more precarious. There is a
very widespread impression prevailing' that the amount pan
for water rates, tire service, and electric lighting is sufficient to
supply the city on a much more ample and liberal scale, and at
the same time secure incidental advantages of great value.
"The project before the city is:
"First. The Construction of a massive dam across the Colo¬
rado to furnish power for pumping, for electric lighting, and pio-
pelling street cars.
"Second. The construction of a reservoir at a height suffi¬
cient to maintain fire pressure in the pipes.
"Third. The extension of the distributing system on a scale
of magnitude commensurate with the present and prospective
wants of the city.
"Fourth. As an incident of the project it is expected that
there will remain a large surplus of power susceptible of such
uses as will greatly promote the future prosperity of the city.
THE DAM.
"The Colorado above Austin flows in a deep cut or canyon
worn in the limestone rock. It is skirted by limestone bluffs
rising often to the height of one hundred and fifty feet above the
bed of the river broken by the erosion of tributary streams. No
extensive meadow or bottom lands exist. This situation permits
of the construction of a high dam with but little damage to pri¬
vate property.
"The river, in its normal condition, occupies but a small
part of the channel in the rock, the remainder being occupied
by alluvial deposits to the depth of average high water. Tn
great floods the river spreads from bluff to bluff.
Several situations have been examined with reference to
the construction of the dam. One on Taylor's lime chute, about
three ;md one-half miles from the city limits, appears most
1 "T ov;tb!e to the construction of the dam itself, but one on the
l>r; e e Tii-i(|e(. property, about three-fourths of a mile nearer
town. ] Nses>es gre;iler advantages as regards the canal and works
a pp< i tment to the water power. This site has been selected for
the purpose of the estimate.
The Austin Dam
11
"The channel in the rock is here about 1150 feet wide at the
height of sixty feet above the summer level of the river. The
cross section of the channel is not far from the level on the bot¬
tom, and is bounded by nearly perpendicular walls of rock
rising to a height of a little over sixty feet on the city side of
the river, and 125 or more on the other side. The river bed
proper occupies not more than one-half of this width, the re¬
mainder of this being alluvial deposit rising to a height of forty
or fifty feet above the river bed. The situation here is admir¬
ably well adapted to the development of water power by a
dam about sixty feet in height, the perpendicular face of rock
rising to about that height and thence receding from the river
in a gentle slope forming a bench on which the canal or feeder
could be constructed, the alluvial strip of ground between the
canal and river furnishing sites for pumping and power sta¬
tions and any other establishments requiring power. An esti¬
mate has accordingly been prepared on the basis of a sixty
foot dam.
"The crest will be about 1150 feet in length [the crest was
really 1091 feet long—T. IT. T.j. It is contemplated to make
it some sixteen feet thick at the top, increasing downward and
spreading out in a broad toe or apron, to give the water a
horizontal direction, making its extreme width at the bottom
about fifty feet. The body and upstream face of the dam is
to be made of limestone rock abounding in the vicinity, the up¬
stream face being of quarry-faced work with close joints. The
downstream face and toe are intended to be of granite found in
abundance in Burnet County, split to approximately regular
shape and laid with but a small amount of tooling. The capping
is of granite in as large blocks as can be handled, worked to regu¬
lar shape. The entire work to be laid in hydraulic cement.
"The Colorado at Austin drains some fifty thousand square
miles, and, of course, carries at times an enormous flow of wa¬
ter. The highest flood within the memory of the people now
living was some 45 feet above low water, and from the best
data I can obtain the flow of the stream was some 250,000 cubic
feet per second. This would imply a depth of sixteen feet on
the crest of the dam, and the abutments should of course go
to that height. At one end of the dam the natural rock goes
12
Bulletin of the University of Texas
far above that height. The other end is occupied by an } 11 ^
ficial bulkhead, called the gate house, containing the sluu.es
for drawing off the water. It is expected that the wash °t
the dam during floods will carry away the alluvial deposit
for a considerable distance. The wheels, for this reason, must
be some two hundred or three hundred yards from the dam,
and the canal must have that height. As already stated,
the formation permits this canal to be excavated in rock. At
the entrance to the canal is the gate house alluded to above. Its
function is to enable the water to be shut out of the canal in
case of repairs and to prevent the canal from being overflowed
in time of floods. The water will be drawn from the canal
through iron pipes, pass the wheel, fall into the wheel pit. and be
discharged through underground races into the river.
WATER POWER.
"It remains to consider the quantity of water power created
by the proposed improvement. This consists of two elements,
the fall and the quantity of water available for power. The
former is fixed approximately by the height of the dam. The
latter can be inferred with more or less certainty from the known
facts. It is not the lowest stage that the river is ever known to
attain to. It is the flow of water that can be depended on, with
reasonable certainty, during the ordinary seasons. Stages of the
river above this minimum count for nothing unless steam is used
to make up deficiencies.
The river is subject to great rises in times of heavy rains.
On the cessation o:i the rains it falls rapidly until it attains a
minimum flow, which appears to remain nearly constant. In
that condition no water enters the stream from the surface of
the ground. Its flow is wholly maintained by spring issuing
from cavities in the rock, and is unaffected by current rainfall
until the latter becomes sufficient to cause a flow from the
ground. This is the present condition, and I conclude we shall
not be far wrong in taking the present flow of \\le '
the quantity that can be depended upon. This, as I }Vl, / m
tained by careful measurement, is nearly one thonJ 'ls<i<>,~
„ ^ ' •, 'Ul(l cubic
feet per second.
"There will, no doubt, be times during the hotter
5,1 weather
The Austin Dam
13
when the water will fall below this stage, on account of in¬
creased evaporation. I am told, however, that a month very
rarely passes without rains in some part of the drainage
basin, sufficient to cause a slight rise at Austin. The great ex¬
tent of the pond will enable a considerable deficiency in the
flow of the stream to be made good by storage. From the best
information I can obtain, the pond will extend some 30 to 35
miles from the dam, with an average width of one quarter of a
mile, containing a water surface of some eight square miles, and a
total volume of something like 2,800,000,000 cubic feet of water.
Should the flow of the stream diminish one-half the above quan¬
tity, a single foot in depth on the pond will make good the de¬
ficiency for a period of five days, and six feet will make it good
for thirty days.
"A system of fiasliboards could be readily applied to hold the
water four feet above the crest of the dam. and thus hold the sur¬
plus of water in store for such deficiencies, without drawing the
pond below the crest of the dam. This feature will not become
necessary for several years, and need not be considered further
at present.
"Owing to the imperfection of mechanism we can not hope to
utilize for practical purposes, more than eighty per cent of
the absolute power of the water. Moreover the full head of
sixty feet can not be brought to act upon the wheels. Some part
of the head will be consumed in the movement of the water
through the sluices, canal, penstocks, and races. The head will
at times be reduced by the high water in the river, which rises
more below the dam than above. I therefore take 5 7% feet as
the head acting on the wheels, and assume that we can utilize
eighty per cent of the power on that head. This gives for the
total amount of power available for driving machinery,
57.5x62.5x1000 „ coor7 T
—— x0.80=5227 horsepower.
550
This quantity of power could be furnished constantly night and
day. This, however, would not be suited to the requirements
of industry, which ordinarily calls for power only during the
working hours of the secular day. It is regarded as a great ad¬
vantage in water power to be able to hold back the low-water
flow of the streams during nights and Sundays, and use it dur-
14
Bulletin of the University of Texas
i1114' the working hours. This the great extent of our pond readily
enables \is to do. Concentrating the entire weekly flow of the
stream into the working bourse assumed at sixty per week, the
above amount is increased in the ratio of 60 to 168, giving as
available power 14.(536 horsepower.
"The total permanent power of the Merrimac River at Lowell,
Massachusetts, is not over 11,000 horse-power, on an average,
during working hours; about the same at Lawrence, Massachu¬
setts, and at Manchester, New Hampshire. This is the power
that can be supplied without interruption. At these points the
use of water is not confined to the minimum flow of stream. It
is utilized at much higher stages in connection with steam, the
latter being called into use when the flow diminishes. Of course,
similar methods will prevail here as soon as the demand for
power warrants their introduction.
"It is not easy to state the rental received for water power at
the great manufacturing centers in New England, as grants of
water are usually covered with grants of land, the water being
regarded as an easement of the land. A round sum was paid
for the land and a normal rent for the water, which was in¬
tended as the fund for the maintenance of the appliances of the
water power. When the manufacturers draw in excess of their
grant, they are charged all the way from $3 to $12 a day for
mill power for water terminable at will. My opinion is that
$1,200 per annum fairly represents the value of a mill power.
These considerations are referred to as showing the great value
of the incidental benefits secured to the city by this improve¬
ment. The city's requirements for pumping is put at 600 horse¬
power twelve hours per day, or <20 horse-power ten hours a day.
Reserving an equal quantity for electrical lighting, and an
equally liberal piovision for street ears and other purposes,
there would remain over 12,000 horse-power, or as much as 180
mill powers, subject to such use as the city might deem conducive
to its prosperity.
ESTIMATED COST.
"Dam $463,325
Gate House 99
CaIial 49 J 50
Pumps and Power House o
500
The Austin Dam
15
Wheel Pit
Culvert
Wheels and Pumps
Filtering Gallery
Reservoir
Mains
Distribution
Electric Light
Add for Contingencies
Add for Engineering and Agencies
2,123
10,210
16,025
17,880
104,615
153,800
295,250
45,600
118,502
59,251
'1 Grand Total
$1,362,781"
On April 3, 1890, the Board of Public Works was created by
the city council, to have control of the construction of the dam
and of all works connected therewith.
The question of issuing Water and Light bonds to the amount
of $1,400,000 was submitted to the voters of the city of Austin
on May 5, 1890, and resulted in 1,354 votes in favor of and 50
votes against the issue. The Board of Public Works met next
day and employed Mr. Frizell as chief engineer and Mr. -T. F.
Pope as first assistant engineer. In order to guard against pos¬
sible errors, and to have the advantage of the skill and experi¬
ence of other experts, Mr. .Tno. Bogart of New York was em¬
ployed as consulting engineer to examine the site and the plans
and specifications of Mr. Frizell.
After an extended examination Mr. Bogart made a written
7'eport to the board, in which he stated that after considerable
study he was of the opinion that the site selected by Mr. Frizell
was the best place for the location of the dam. In regard to the
cross section and shape of the dam Mr. Bogart said:
"Ample precedents exist for the determination of the best
lines of profile and methods of construction for such a dam.
It will be one of the high dams, but will not be among those
very high structures which sometimes excite doubt as to their
permanent stability. To provide for the possible height of
spring or other floods, the whole crest of the dam will be formed
so that the water may flow over it, and the downstream face
will be built in such a manner and to such lines and curves as
will tend to conduct the overflow to the lower river without
Ui Bulletin of the University of Texas
damage to the stability of the structure. It is estimated that the
highest flood as to which any information can be obtained might
give a depth of water of fifteen of sixteen feet over the crest
for a short time. Such a possible flow will be provided for in the
construction of the dam. The exact lines of the profile and the
detail method of construction are now being determined in
consultation with Mr. Frizell."
During the summer of 1890 engineers" were put in the field
to locate the lake-level contours and to determine the amount of
valuable land submerged. Those engineers took cross sections of
the river at sixteen stations, thus enabling comparisons to he
made, as was done by the writer in May, 1897, and in January,
1900. The accuracy of the work under the supervision of Mr.
Pope was verified by the fact that at the head of the lake, at
the request of a farmer living near, he cut a bench mark on
a big pecan tree, at the crest level. Three years later the water,
when it rose to the crest of the dam, reached the notch with
exactness. Cross sections of the lake are shown in Fig. 6; a
general map of the lake is shown in Fig. 5.
On October 15, .1890, the contract for the construction of the
dam was awarded to the lowest of seven bidders, Mr. Bernard
Corrigan, of Kansas City, Mo., whose figures were $501,150.
The contract was based upon the following specifications:
HOCK EXCAVATION
"12. On the site of the dam all unsound rock and all rock
that can be removed without blasting will be taken off. A
trench four feet wide, and as deep as may be directed by the
engineer, will be excavated along the upstream face of the dam.
Trenches, footings, steps, channels, and other excavations will be
cut in the bottom and sides of the rock in such forms and to such
lines as may be directed by the engineer. In those excavations
the kind of explosive used, the amount of the charges, depth and
direction of the holes, and the entire process of the work shall
be under the immediate personal control of the engineer or his
assistant, the object being to do the work in such manner as to
avoid fissures and shakes in the remaining rocks All cracks
and fissures that may exist naturally or from any eause shall be
The Austin Dam
17
thoroughly tilled with cement mortar or concrete or pure cement,
as may in each case be directed by the engineer.
"13. The lines and grades of the canal will be established
by the engineer, and no excavation below the grade or bottom or
outside the lines will be paid for; but such excavation will he
permitted under the direction of the engineer, for the purpose
of obtaining rock for the dam.
" 14. Any rock obtained from these excavations that the engi¬
neer may deem suitable may be used in the rubble masonry of
the dam. Rock not suited for this purpose will be disposed of
as the engineer may direct—in spoil bank, riprap, filling of
cribs, or otherwise not involving a haul of more than 500 yards.
The price of rock excavation will include and cover the cost
of all the explosives, tools, derricks, tackle, machinery, teams,
vehicles, tramways, stringers, bridges, boals and appliances,
materials, and labor used in the excavation of the work. All
rocks will be measured in excavation.
MASONRY.
"15.. The upstream face of the dam will be laid in granite.
[The original specifications called for fossiliferous limestone for
the upstream face, but bids were also received for granite,
which material was adopted. The details here given are ob¬
viously not proper for granite.—T. U. T.] It must be sound,
free from seams, cracks and shakes. The stones will be
laid on their quarry beds in regular courses, no course to be
less than twelve inches in height. Each course shall be composed
of headers and stretchers, ancl at least one-thircl of the face
length of each course shall be headers. The headers and
stretchers shall be regularly distributed in each course, so that
the headers shall alternate in position in the adjacent courses
and so that each stone shall break bond not less than twelve
inches with the stone above and below. A gamut or plan for
each course will be prepared and submitted to the engineer
before the stones are laid, and if approved by him, will be user)
for the guidance of workmen in laying the stones. This will
be quarry faced work. Each stone will have a distinct pitch
line all around the face. The bed and build joints will be fine
pointed to a fair, true surface, out of wind, nine inches back
2-164
18
Bulletin of the University of Texas
from the pitch line. The remainder of the bed and build joints
to be pointed, so as not to project beyond the plane of the fair,
true surface and not to fall away therefrom more than one and
one-half inches. The width of the stretchers on their beds will
not be less than their height. No stretcher will be less than 3
feet in length. The headers will not be less than thirty inches
on the face nor less than four feet in length. This work will
be laid with full mortar joints on the beds. The mortar will be
pressed or tampered into the build joints with a proper tool.
After the work is laid the mortar will be raked out of all exposed
joints to a depth of one and one-fourth inches, and these joints
will be pointed with mortar of neat cement pressed in and rubbed
hard.
"16. In measuring this work, the headers will be accounted
four feet long. The width of each stretcher will be considered
equal to its height. No stone of less dimensions will be laid.
If stones are laid exceeding Ihese dimensions the excess will be
paid for as rubble filling.
"17. The downstream face of the dam is to be laid with
granite of good quality, sound and free from imperfections. It
will be laid in regular courses; no course to be less than twelve
nor over thirty inches high. Each course shall be composed
of headers and stretchers, and at least one-third of the face
length of each course shall be headers; the headers and stretchers
to be regularly distributed in each course so that the headers
shall alternate in position in the adjacent courses, and so that
no stone shall break bond less than twelve inches with the stone
above and below. The stretchers shall be as wide as high, meas¬
ured on the lower bed, no stretcher to be less than three feet: no
header to be less than three feet on the face and four and one-
half feet long. On the curved part of the face, except at the toe
the bed joints shall be radial. On the vertical and battered p-irt
they will be horizontal. Dowels and clamps of wrought iron will
be inserted at the toe, as directed by the engineer.
"18. The exposed faces of all these stones are to ha
distinct pitch lines all around; the face not to project or n. \ ]
more than one and one-fourth inches from that line- ult | j
and builds to be pointed off to lay a three-fourth inch joint 1'
twelve inches back from the pitched line.
"19. If this work is laid with fossiliferous marblp +v,
the specifi.
The Austin Dam
If)
cations will be the same in every respect as for granite, except
that the beds and builds will be dressed to a three-eighth inch
joint instead of a three-quartei* inch joint. Bids will be received
for either kind of stone. A gamut or plan of each course will
be prepared as specified for the upstream face.
"20. In measuring this work th^ headers will he taken as
four and one-lialf feet long, the stretchers as wide as high, meas¬
ured on the lower bed. No dimensions less than these will be
accepted. If stones of -greater dimensions are laid, the excess
will be paid for as rubble filling. All of this work is to be laid
in cement mortar.
RUBBLE MASONRY.
"21. Rubble masonry will be laid in the body of the dam.
This will be composed of any firm, strong and sufficiently heavy
stone. It must not weigh less than 150 pounds per cubic foot.
At least two-thirds of it must consist of blocks having a bed of
less than four square feet. Smaller stones may be used to fill up
the spaces between blocks. All stones must be bedded in mortar
and all interstices filled with mortar. Such practice as laying-
down stone and pouring gout into the cavities will not be allowed
and the inspector will require such work to be torn up and relaid
whenever discovered. The rubble work will be well bonded with
masonry on the up and down stream faces. The trench along
the upstream face of the dam will be filled with fragments of
granite ["or fossil if erous marble" erased in specifications],
of any form and size, carefully laid in cement mortar. Should
distinct veins or streams of water enter this trench, the water
will be allowed to rise through earthenware drain-pipes set in
the masonry, or through openings left in the masonry, and dis¬
charged above the dam.*
"22. The capstones will be of granite of the best and soundest
quality, free from all imperfections. They will be three feet in
depth, not less than three feet wide, measured length-wise of
the dam, and each cap will consist of not more than three sfones.
The stones of the adjacent caps will break beyond twenty-
four inches. A distinct pitched line "will be cut around the
weather face, following the outline of the stone, as shown on
*This paragraph is eliminated from specifications.
20
Bulletin of the University of Texas
the plan. The weather face will not be more than one inch out
as regards this line. The stones will be bedded in mortar, the
build joints will be filled up with melted sulphur, oi quality
appi'oved by the engineer. Dowels of wrought iron w ill be
inserted as indicated on the plan, and also bedded in sulphur;
the stones will be fastened together on the top with wrought iron
clamps and dowels as directed by the engineer.
"23. The price of masonry will include furnishing the
stone, cement, and sulphur and all material and labor required
for the excavation of the work as herein provided.
"24. Before commencing the laying of any masonry the
rock on which it is to rest must be swept and washed clean with
brooms, and the same must be done when new masonry is joined
on to the old. All stones must be washed before being laid in
the work. A tank and other appliances satisfactory to the
engineer must be provided for this purpose.
"25, The cement furnished for this work must be from
manufacturers of established reputation, and such as has satis¬
factorily stood the test of time and experience. It will be sub¬
jected to such tests as the engineer may require from time to
time, and such as is rejected must be immediately removed
from the work. Quick-setting cement will not be used. Cement
showing on chemical analysis magnesia or lime in proportion
sufficient to injure the work will be rejected. American natural
cement will, in general, be expected to exhibit a tensile strength
of fiity pounds per square inch at the end of thirty days, when
mixed with twice its bulk of sand. Portland cement will be
expected to show a strength of 150 pounds per square inch at
the end of thirty days when mixed with three times its volume
of sand. Cement shall be stored in sheds sufficiently water
tight to exclude rain, with floors raised at least twelve inches
above the ground, and permitting a free circulation of air To
give opportunity for tests the contractor shall have no less than
sixty days' supply of cement on hand at all times rOnlv
Portland cement was used.]
mortar,
"26. The mortar is to be prepared from cement of the
above described and clean sharp sand, free from loam 1 1 ^
0r other
The Austin Dam
21
impurities, in the proportion of one part cement to two parts
sancl, by measure. If made bv hand it is to be mixed dry, and
a sufficient quantity of water afterwards added to produce a
paste of proper consistency, and thoroughly worked with hoes
or other suitable tools. If required the contractor shall provide
a mortar mill or such form as the engineer may prescribe, to be
worked by steam or horsepower. The mixing of the mortar will
he under the constant supervision of an inspector. Sand offered
for Ihe work shall be washed and screened, if the engineer shall
so direct, in such manner as he shall prescribe.
"40. And the said contractor hereby agrees to receive the
following prices as compensation for furnishing all materials
and for labor in executing all work contemplated in this eon-
tract, and for all risks of loss incident to the nature of the work,
to floods and freshets on the river, or to other action of the
elements, to strikes and combinations of workmen, to changes
in market values during the progress of the work, and to all
other causes.
"(a) For bailing and draining, including the construction
and maintenance of all necessary cofferdams, the furnishing,
setting, and operating of steam engines, boilers, and pumps,
and all labor and material required for the removal and exclusion
of water from the work during its entire progress, as specified,
the sum of $8000.
"(b) For all earthwork excavation above the low water
level of the river, including the disposal of the same in spoil
banks or in cofferdams, and all clearing and grubbing, the
sum of 14 cents per cubic yard.
"(c) For all earth excavation below the low water level of
the river including the disposal of the same, the sum of 50
cents per cubic yard.
" (d) For rock excavation on the side of the dam, including
the disposal of the rock in spoil banks, riprap, or otherwise, as
may be required, the sum of .$1.60 per cubic yard.
"(e) For rock excavation from the eaual and site of gate
house, including the disposal of rock, the sum of 80 cents per
cubic yard.
"(f) For the masonry of the upstream face of the dam, of
granite cut. and laid as specified, the sum of $11.00 per cubic
yard.
Bulletin of the University of Texas
"(g) For the masonry of the downstream face of the dam
of granite the sum of $11.25 per cubic yard.
"(h) For rubble masonry laid with stone paid for as
excavation, $2.50 per cubic yard.
" (i) For rubble masonry laid with stone not paid for as
excavation, the sum of $3.50 per cubic yard.
"(j) For rubble masonry laid with granite in trenches, the
sum of $6.00 per cubic yard.
" (k) For the granite capstones dressed and laid as per speci¬
fications, the sum of $15.00 per cubic yard.
"(1) For drilling bolt holes for wrought iron clamps and
dowels, the sum of 24 cents per linear foot of hole drilled.
" (m) For furnishing and inserting wrought iron clamps
and dowels as required by specifications, the sum of 10 cents
per pound.
"(n) For laying masonry of any kind in Portland cement
mortar in excess of the price received for the same work laid
in mortar of American natural cement, the sum of 50 cents per
cubic yard. [There were more than 90,000 yards in excess.!
"41. And it is further agreed that the engineer shall make
approximate monthly estimates of the work done, and the
materials delivered, and the payments shall be made of 85 per
cent only of the amount of such monthly estimates.
"42. And the said contractor hereby further agrees that the
said board be and is hereby authorized to deduct and retain out
of any money due the contractor the sum of $500 per day as liqui¬
dation damages for each and every day the aforesaid work shall
remain uncompleted beyond the time herein stipulated for its
completion; provided, however, that the board shall have the
right to extend the said time, should it decide to do so.
43. And it is further agreed the sum agreed on as compen¬
sation for bailing and draining, three-fourths shall be considered
as earned when the entire masonry is raised to a height of
three feet above the low water level of the river, and the remain¬
der when the dam is fully completed according to the terms of
this this contract, and that these sums shall be subject to the
above-mentioned deduction of tifteen per cent,
"43a. The power of the Board of Public Works nr.,1 the
engineer acting under them as now constituted 0ni , i
to executing the contract as it is made bv the city : and n ' X S
■ - tina all changes.
The Austin Darn
23
f the contract and final approval of the work done shall be by
tie city council upon the recommendation of the Board of
'ublic Works, or by the proper city authorities that may be
rovided by law from time to time as the work progresses.
"43b. This contract is conditioned upon a railroad being
(instructed by the city or some persons other than the contractor
rom the depots in the city of Austin to the site of the proposed
am, and the said city guarantees to the said contractor the
se of the said railroad track free of charge for hauling all
laterial for the construction of the dam. It is understood that
11 time which may be lost by the contractor by reason of the
on-completion of said railroad shall be credited by said con¬
tractor on the time stipulated for the completion of the dam.'"
The cross section originally adopted is shown in Fig. 2, left
alf. The contractor commenced the work of excavating the
lluvial soil on the east bank on November 5, 1890, and the
rst stone was laid in the foundation of the dam May 5, 1891.
xactly one year after the election authorizing the issue of the
onds. The east half of the dam was built to a safe height
bove ordinary freshets, and then the work was pushed from the
est end. The foundation work at the east end was protected
y a natural dirt coffer dam and at the west end by a wing wall
f broken limestone for body and hay and dirt as tillers. This
efiected water toward the west end of the eastern portion, and
:ie western section of the dam was thus built out to within
short distance of the eastern portion. The gap was closed
y first constructing a small dam in front of it. thus forcing the
ater through a gap in the eastern portion only a few feet
igher than the foundation courses. In this way the water
as played from one gap to the other at the pleasure of the
infractor. The gaps left in the dam while the work of construe -
011 was proceeding were filled alternately. When the
mrses reached a sufficient height, a framework dam was made
> check the flow through the gaps. In September, 1892, three
nice pipes, each three feet in diameter, were built into the dam
: a level forty-three and one-lialf feet below the crest, so that
lere could be no basis for complaint of stopping the flow of
ie river, and incidentally, to assist the contractor in control 1-
ig the water. At a later stage of the construction one of
lese pipes, half open, and under a head of 36.5 feet, passed the
Bulletin of Ike University of Texas
whole flow of the river. The dam cost over $110,000 more than
Oorrigan's original bid. The causes of this increase were:
1. Increased excavation at east end of dam. . . . $8,914.60
2. Extra masonry 56,793.32
3. Extra limestone masonry 21,839.80
4. Extra allowance for Portland cement 44,180.25
5. Change in shape of crest. . 2,337.45
6. Allowance for pumping, excavating without
explosives and cement 3,385.49
Total 137,450.91
Overestimate 27,255,62
Total extra cost 110,195.29
Original bid ;)01,150.00
Total cost of dam 611,345.29
The plans recommended by Mr. Frizell contemplated a canal
several hundred feet long and a power house south of the site
subsequently selected, located upon the alluvial soil below the
dam. In -January, 1892, it became manifest that some members
of the Board of Public Works did not approve the plans sub¬
mitted by Mr. Frizell in so far as they related to the canal. They
advocated the abolition of the canal, and suggested that the water
be taken directly I rom the lake by the penstocks, and that the
power house be located near the east end of the dam. At this junc¬
ture the board requested Mr. E. C. Geyelin, of Philadelphia, to
visit Austin and report upon the questions at issue. In his report
dated February 17, 1892, Mr. Geyelin recommended, among
other things, that the power house be located upon a rock foun¬
dation at least one hundred feet from the dam, and that the
water be conveyed from the lake by a series of large pipes The
power house was afterwards located at an average distance
of 130 feet from the dam. Mr. Frizell took issue"with these
recommendations, and the board then decided to ask 11 i • '
„f Mr. J. T. Fanning, of Minneapolis. After spending „
weeks in Austin investigating the problems. Mr F- ° •
June 24, 1892, submitted his report to the'bonwi an°lng» 011
other things said: d' and amo"g
"This dam is being constructed of solid mason
faced on each side with large blocks of excellent . *S
for its great length alone or its great area of flowas? ° ^0t
ls the
The Austin Dam
25
clam remarkable, for in France we observe three longer masonry
dams—at Bouzey, Chazilla, and Gros Bois, 1545. 1759, and 1805
feet long respectively—and in Wales the Vyrnwy dam, 1,350
feet long, the latter beinc for the storage reservoir of the Liver¬
pool water supply.
"Not in the height alone, for in France there are three dams,
in Spain two. in Belgium one, and in the State of California
one masonry dam exceeding 150 feet in height. There are
fourteen other notable masonry dams having heights exceeding
one hundred feet. But none of these dams are upon great rivers,
and very few of them have any water pass over their crest.
On the other hand, the Austin dam is in the channel of the Colo¬
rado River, where it has 40,000 square miles of watershed, and
will have floods of 200,000 to 250,000 cubic feet of water per
second to pass from its crest to its toe. Your citizens will appre¬
ciate your responsibility when they learn that no dam in
existence has to pass a volume of water, in flood, even approxi¬
mating this, through so great a height. Limestone and sand¬
stone yield rapidly to the eroding force of falling waters. The
evidences of this are abundant in the canyon of the Niagara
River below Niagara Falls, in the canyon of the Genesee River
below the Genesee Falls, the Mississippi River below St.
Anthony Falls, and here of the Colorado River across Travis
County, as well as in the channels of numerous streams thai
flow down each of the Rocky Mountain slopes. Such evidences
admonish us that this great flood must not be permitted to have
a sheer fall through so great a height and act with a destructive
force such as heretofore created canyons, but it must be made
to glide down the slope of. the dam and not be permitted to
exert the force due to its velocity except at such distance below
the dam that the foundations will not be endangered.
"The profile (fig. 2, left half) as shown to me seems not to
fulfill the required conditions for passing the floods, because of
the slightly rounded or nearly angular form at the front of
its crest. Another diagram (fig. 2, right half) presented
shows an advised modification of the profile of the upper part
of the dam, which is better adapted to pass the flood in a gliding
sheet down the face of the dam and to deliver it to the lower
level without a direct blow, and so that its velocity will be
26 Bulletin of the University of Texas
Cross-Sections of Dam; Left Side as Proposed by Frizell; Right Side as
Constructed by Fanning".
expended chiefly in a horizontal direction in the back water
below the dam and in eddies at a safer distance below the toe
of the dam. The lower part of the downstream face of the
dam has a curve of 31 feet radius to which low-water surface is
tangent. The central part of this face haS a batter of four and
one-half inches to the foot.
"The new profile at the top part, as suggested, completes
the downstream face and crest of the dam with a curve of
twenty feet radius, to which both the front batter and the surface
of the pond at a level of the crest are both tangent, this curve
ending on the crest at five feet from the upper angle of the
crest. The upper angle of the crest is then rounded off with a
smaller curve, and the entire front of the dam becomes a reverse
curve of ogee form, the form of dam best of all adapted to pass
a large volume of water through so great a height. The top
curve conforms nearly to the theoretical form of a medium
flood stream. At the higher flood stages there will be tendencv
to vacuum under the curve stream immediately after it has
passed the crest, which, together with the pressure of the atmos
phere upon the top of the stream, will keep the flood stream in
full contact with the curved face of the dam, and can so
' ^duse even the
highest flood to glide clown the fall without shock upon th( f
of the dam or the soft rock foundation."
In addition to this. Mr. Fanning recommended that tv,
16 power
The Austin Dam
27
house be located in the position shown in Fig. 4, and that the
river side of the power house rest on a granite revetment wall
250 feet in length, 1o protect it from the force of the water.
The Board of Public Works finally determined to change the
cross section of the dam to that shown in Fig. 2, right half, to
locate the power house near the east end of the dam, and to
take the water from the lake through nine foot penstocks. The
head-gate masonry before May, 1898, is shown in Plates II, A,
which also illustrates the positions of the wrought-iron pen¬
stocks.
The best modern appliances were used in the construction of
the dam. The granite material for the facing was obtained
from Granite Mountain, near Marble Falls, being hauled from
the quarry to the dam over the Austin and Northwestern Rail¬
way, a distance of seventy miles, and delivered at the east end
FIGURE 3
Saddle Used in Construction of Austin Bam.
Bulletin of the University of Texas
of the dam. The granite blocks were of average dimensions and
weighed four tons each. The four classes of material used i. e..
Ihe limestone rubble, the cement, the sand, and the granite were
transferred from the end of the dam to their place by a cable two
and one-half inches in diameter, stretched between two towers-
one on the east and the other on the west of the bluff—1350
feet apart.
The cable was anchored to "dead men" at the ends, weighted
down by stone. The saddle shown in Fig. 3 was especially
designed for this work, and ran on the main cable. The wire
ropes were known as the "hauling rope, the "hoisting rope,'
and the "button rope." The hauling rope was attached to the
lower part of the frame work of the saddle, passed over pulleys
at both towers, and wound around a drum under the east tower.
The endless hauling rope was operated by an engine to which its
drum was attached. It was completely under the control of the
operator, and could be stopped in any position along its course.
After being checked in the position desired, the drum operating
the hoisting rope was brought into motion, and the load was
lowered to the dam.
The granite blocks and the larger limestone rubble stones
were handled by immense tong-like grips. The cement and sand
were loaded into cages, transported to the place of construc¬
tion, and there dumped on the dam. The cement mortar was
made at the place where it was to be used, and the blocks of
masonry were placed by crane derricks.
A wire rope one-half inch in diameter was used in connection
with the cable and saddle to prevent excessive vibration of
the operating ropes. On this rope were buttons which increased
in size from the tower to the west. The hoisting rope was sup¬
ported at different points by carriers which rested, when the
saddle was stationery, on the main cable. This carrier consisted
essentially of two parallel bars, between which and near the
lower end a small pulley was supported to carry the hoisting
rope. A series of slots were arranged in the upper part 0f the
carrier through which some of the buttons could pass When
near the east tower the saddle supported all the carriers except
the last, which it took off the horn; the second button passed
through all of the remaining slots except that in the second car¬
rier. which it pulled off the horn; and so on. The carriers were
B. Methods Used to Stop Leak.
Th< Austin Dam
thus stripped oft' the horn by the buttons and rested on the
main cable, affording a groove or support for the hoisting rope
and reducing ils vibration.
LEAK UNDER HEAD GATE
On May 30, 1893, the water from the lake cut under the
east bulkhead and undermined the proposed foundation of the
power house. It entered a seam in the limestone slightly
*."-09--1 N
FIGURE 4
Plan of Power House and Penstocks.
Fig. 4.—Section and sketch plan of bulkhead, showing location of
power house and penstocks. HK is bottom layer of concrete filling rest¬
ing on hard limestone strata; HM is line of crack; RS is the original
level of the bulkhead masonry; RSTU is tunnel (6 feet by 6 feet by
60 feet long) filled with concrete; A is point where drift indicated leak
in the spring of 1899; HB is location of leak discovered in the fall of
1S99: P is point from which view shown in PI. Ill, B, was taken; FG
is wing wall; C is ten-inch horizontal pipe projecting from wall of
power house, known as "the spring;" D is cement chamber of controllng
water and directing through C; 1 to 7 are penstocks; E is the point at
which the leak in penstock was found in February, 1900.
J>ull(li)i of the rnivcrsitij of Texas
above the point, indicated at K in Fig. 4, about ninety feet from
the dam. From his point the course of the water was at an
an^le of about thirty degrees to the axis of the river to the
left (looking down stream), and it also took a downward course
and passed about twenty-five feet under the foundation of the
head-gate masonry. The water issued from the west wall of
the proposed power-house foundation and soon wrecked it.
The general course of the water was from a point near the
east end of the head-gate masonary, diagonally across the
foundation to the point of exit.
A coffer dam about 12.") feet long was constructed of frame¬
work, with dirt and hay as fillers, from a point on the shore
above the entrance to the crevice to a point near the end of the
dam. This effectually cut off the water from the proposed
forebay, and the work of repair commenced. As originallv
designed, the head-gate masonry contemplated nine large
pipes, but only seven were put in.
The head-gate masonry cracked about forty feet from the
end of the dam, along the line IIM in Fig. 4. and settled. The
earth east of the east end of the head-gate settled for a distance
of tweny-five feet. Plans were immediately adopted for raising
and strengthening the coffer dam so as to provide against
floods, for rebuilding the head gate, and for the construction
of a power-house foundation. The broken part of the head-
gate masonry was removed (leaving only that over penstocks 1
and 2), and an excavation nearly two hundred feet long and
seventy feet deep, with an average width of seven feet, was
made. 1 his trench reached 1o a level of .>/ ieet below the crest
of the dam, or within three feet of the level of the toe. The
head-gate masonry was rebuilt, provision being made for only
nine-foot penstocks, the rest of the excavation being filled by
a concrete wall 112 feet long, which was eight feet thick for
the ninety feet next to the head-gate and only five feet thick for
the rest oi the distance. In excavating tor this extension wall,
alternate layeis of hard and soft limestone were encountered,
as shown in 1 1. II B. 1 he bottom layer of the concrete filling
(IlK, Fig. 4) was laid on one of these hard strata, but it was
fully demonstrated that a current of water was running uiuler-
B. Flood of June 7, 1899. Lake Level 9.25 Feet Above Crest of Bam.
The Austin Dam
31
neath. Several holes were drilled, through which the water
welled up in jets several inches high. However, it was thought
safe to plug these holes and to ignore the stream below. The
bulkhead masonry originally extended to the level BS, Fig. 4,
thirty-six feet below the top of the dam; but as an extra pre¬
caution a tunnel (RSTU) six feet square and sixty feet long
was cut under the bulkhead masonry back to the end of the
dam proper and the space was filled with concrete. The space
below the forty-two-foot level under the tunnel was not dis¬
turbed.
The foundation for the power house was then excavated to a
depth of more than eighty feet below the crest of the dam. The
original contractors, after a dispute in regard to the excess of
water flooding their work, surrendered their contract. The new
contractors succeeded in controlling this water by the use of a
cement chamber at 1). Fig. 4, and a ten-inch horizontal pipe,
which projects from the wall of the power house at the point C,
about fifty-four feet below the crest of the dam. This is often
referred to as the "spring." A view of it is shown in PI. Ill,
A, where it is being discharged through a ten-inch pipe in the
third course of granite above the toe of the dam. Measurements
taken in October, 1895, showed a range on the horizontal sur¬
face of water in the tail-race of 5.1 feet and a fall of 5.8 feet,
giving a discharge of 4.6 feet per second. A 3,000,000-gallon
pump entirely exhausted this "spring." In May, 1893, the flow
from the so-called "spring" suddenly increased. An average
of several measurements" gave a range of 11 feet and a fall of
5.8 feet, and therefore a discharge of about ten second-feet.
Measurements recently taken give a range of 8.8 feet and a fall
of 5.8 feet, and therefore a discharge of eight second-feet.
In the spring of 1899 it was discovered, from the behavior
of di'ift, that water was disappearing from the lake at point A,
Fig. 4. This source of leakage was stopped by filling the lake
at that point with clay, loose and in bags. While the filling in
was going on the discharge of water from the ten-inch pipe
almost ceased for a few hours, but soon reached its normal
amount. The filling kept the water discolored and muddy.
In the fall of 1899 it was noticed that water was disappearing
at point B, Fig. 4. only a few feet from the shore. A coffer
Bulletin of the University of Texas
dam of sheet piling was constructed around this point and it
was filled with hay and earth. A view, taken from point P,
Fig. 4, of the two leaks and of the method of filling by clay and
sheet piling, is shown in PI. Ill, B. The clay filling is the pile
of dirt adjoining the upstream face of the dam.
Tn the latter part of December, 1899, the earth in front of
and between the power house and bulkhead, and at point E,
Fig. 4, began to sink and to continue to sink until it was deter¬
mined to remove the earth covering the nine-foot penstocks
under the sunken areas, in order to discover the cause. The
removal of the earth showed that penstock No. 3 (Fig. 4) was
buckled, and that at one place it had sunk about twenty inches.
A bold stream of water—at least one second-foot in amount and
sixteen feet below the top of the dam—was found when the
earth was taken out between the power house and penstock No.
3 and between penstocks Nos. 3 and 4. The stream of water
was partly deflected around the north end of the power house
and under penstocks Nos. 1 and 2. The water did not rise in
the excavation, and it was discharged through some two-inch
pipes at F, Fig. 4, fourteen feet below the crest of the dam,
through two or three other small pipes, and by absorption
through the wing wall FC and through the east wall of the
power house. Penstock No. 5 was also found buckled at a point
about thirty-five feet from the bulkhead. The water which
caused the settling came from a broken two-inch pipe tapped
into the bottom of penstock No. 5. The break was at an elbow
just below the penstock, at a point about sixteen feet below the
crest of the dam and forty feet from the south side of the bulk¬
head masonry.
ECONOMIC ASPECT.
I he population and taxable wealth of the city at various times
is shown in the following table:
Th< Austin Dam
83
POPULATION AND TAXABLE WEALTH OP AUSTIN, TEXAS.
Year.
1890.
1891.
1892.
1893.
1894.
1895.
1896.
1897.
1898.
1899.
1900.
1901.
1902.
1903.
1904.
1905.
190(1
1907.
1908.
1909.
Assessed Value of
Real Estate.
Assessed Value of
Personal Property.
Total Assessed
Value.
$ 9,990,643
8,935,552
10,514,188
10,773,723
10,881,930
11,025,368
11,384,734
12,085,507
11,532,716
10,844,471
12,377,292
8,831,837
9,030,106
8,847,569
9,135,994
9,650,457
9,831,147
10,627,554
12,460,896
13,690,326
17,369,037
Before the issuance of ttie .-M ,400,000 of water and light bonds in 1890. the bonded in¬
debtedness was as follows:
Six per cent bonds due in 1901 12.5(H)
Six per cent bonds due in 1905 --- 40,000
Six per cent bonds due in 1925: --- -- --- - - 72,500
Total
__*125,000
On May 5, 1890, the city authorized the issuance of $1,400,000
water and light bonds at five per cent. The first $400,000 were
sold on October 15, 1890, to a syndicate of local capitalists at
par and accrued interest. In April, 1892, the Union Trust
Company bought $500,000 of the bonds at 95 cents on the dollar,
and in 1893 Bernard Oorrigan bought $62,000 of them at 95.
Later, in 1893, $388,000 were sold at 92 and $50,000 at par.
TOTAL RECEIPTS FROM BONDS.
450
bonds,
at
par
562
bonds,
at
388
bonds,
at
92
356,960
Total $1,340,860
The break in the head-gate masonry and the destruction of
the first foundation of the power house caused an outlay of
$97,000 above all expectations, and it was apparent that another
issue of bonds would be necessary to complete the enterprise as
originally contemplated.
3-16!
Bulletin of the University of Texas
The $200,000 of bonds issued in 1895 were utilized in paying
the $56,000 indebtedness left by the Board of Public Works,
and in completing the water and light system, with the exception
of the reservoir. The reservoir was never built. After a site
had been practically chosen it became evident that it would be
necessary to filter the water of the lake, and upon the advice
of Mr. Allen Hazen of New York, the sanitary engineer called
m for consultation, it was determined to construct the filtering
galleries in the sand flats about two miles below> the dam, and
to transfer the new pumps to a new house to be erected near
the filters. These galleries, three in number, were in successful
operation when the dam broke. The lower station was equipped
with a 6,000,000-gallon pump and a 300-kilowatt synchronous
motor, which cost $29,380. The filtering galleries and connec¬
tions cost, in round numbers, $21,000.
On January 1, 1910, the bonded debt of the city of Austin
was:
Dam bonds -- - ---- - — $1,359,500
High School Bonds - --- 45,000
1884 Bonds 52,500
1895 Refunding Bonds _ -- -- - - - -- 72,500
Total - $1,529,500
No better idea can be given of the operation of the plant than
to append a report for the twelve months endinir November 30,
1899:
KARXIXfrS.
Water - - - $40,309 39
Light 30,192 61
Power 17,777 14
Miscellaneous ___ ___ 1,203 86
Total - - -_ - $84,546 00
Collected in Cash $67,298 12
Due by City 12,745 19
(xarnisheed Accounts 2,836 70
Due on Bills, etc. __ _ ...... _ 1,665 99
Total _ $84,546 00
For the purpose of comparison, the receipts and expenditures
for the last three years of the life of the dam are here tabulated:
RECEIPTS AND DISBURSEMENTS OF POWER PLANT AT AUSTIN, TEXAS.
| " |
I I Operating Total
\ear Ending. Receipts. Expenses. Extensions. Disbursements
i_
Nov. 30, 1897 $82,059 $36,709 $57 821 $94 530
Nov. 30, 1898 1 93,651 36,239 38 7H , 74'or,3
Nov. 30, 1899 I 82,927 . 39,742 34 719 74'i",4
The Austin Dam
35
Under the direction of the Board of Public Works the follow¬
ing expenditures were made in constructing- dam. water and
light systems:
DISBURSEMENTS.
Engineering expenses __ _ if 58,402 37
Dam (ill,313 39
Electric light dynamos 7,700 55
Electric power generators -- 6,708 5(1
Belting 43 81
Penstocks, head-gate castings, etc. 47,792 19
Power house 45,917 1)8
Draft-tube excavations --- 2,314 OS
Pump foundations 058 60
Bonds 1,237 50
Head gates 2,122 00
Sluice pipes 2,420 1?-
Repairs on account of break 90,941 23
Wheels, pumps, etc 43,418 01
Cuntersliafting, pulley, etc 1,200 85
Water distribution system 158,081 04
Electrical distribution system 115,678 20
Railroad 87,431 90
Office expenses 10,170 03
Submerged lands 27,732 15
Head-gate masonries 46,934 17
Power-house foundations 11,527 00
Miscellaneous - 5,375 74
Total $1,391,129 64
The Board of Public Works was discontinued on the comple¬
tion of the dam in 1893, and the city council then assumed con¬
trol and managed the plant until the Water and Light Commis¬
sion was created by charter in 1897. At the time the Board of
Public WTorks was abolished there was due and unpaid on con¬
tracts the sum of $55,896.87. The Water and Light Commission
had exclusive supervision, management, and control of the
waterworks system, the electric lights, the power plant, and all
property, funds, and business belonging or pertaining thereto.
1909 ANNUAL REPORT.
WATER, LIGHT, POWER,
A. CONSUMERS.
Tear.
Water.
|
.Light.
Arc-lamps.
3 Phase Motors.
January 1, 1909
3,920
1,766
193
566.75 h. p.
January 1, 1910
4,159
2,074
225
593.75
Increase
239
308
32
27.00
36
Bulletin of the University of Texas
B. EARNINGS.
Year.
Water.
Light.
Power.
Miscellaneous.
Total.
Due Jan. 1, 1909
Earnings 1909
$ 63,716 31
122,152 98
$ 87,408 90
99,568 23
$ 2,337 29
11,096 61
$ 149,79
5,008 27
$ 153,612 29
237,825 40
Totals
$ 185,869 29
$ 186,977 13
$ 13,433 90
$ 5,158 06
$ 391,437 69
$ 2,245 11
183,624 18
159,190 28
24,433 90
$ 444 27
186,532 86
161,572 14
24,960 72
$ 118 51
13,315 39
13,196 88
118 51
$ 2,807 89
388,629 80
339,116 67
49,513 13
Net Earnings- - -
Collections
Due Dec. 31
5,158 06
5,158 06
0.00
C. SE1
'T I.EMENT
WITH CITY.
April 1, 1909 iDue City Account Old Company $ 295,869 00
April 1, 1909 Due by City 137,536 41
April 1, 1909 Net Balance due City $ 158,332 59
D. COLLECTIONS.
Total Collections $339,117 36
On City Account 137,536 41
Actual Cash Collections $201,580 95
E. ACCOUNTS PAYABLK.
Due City on Old Company Account $158,332 59
Due for Coal, Material, etc — 3,406 03
Total due $161,738 62
SUMMARY OF EXPENSES.
BETTERMENTS AND EXPENSES—OPERATING AND MAINTENANCE.
Items. Water.
Electric. Total.
Plant betterments
Plant operation- - _ _ _ _
Plant maintenance - _ - .
Lint extension -- „ _
Line operation „ - - __ __ . _
Line maintenance - _ __
$ 19,932 66
14,858 1 9
5,274 63
11,056 88
6,657 73
21,021 45
$ 6,120 98,$ 26,053 64
28,027 21 42,885 40
6,162 90, 11,437 58
8,271 71 19,328 59
11,536 94: 18,194 67
9,425 32 30,446 77
$ 78,801 59
$ 69,545 06 $ 148,346 65
PLANT BETTERMENTS.
Water.
Electric.
Temporary labor $ 1,226 85 $ 652 46|$
Machinery and equipment , 434 55 6,238 721
Eixed salaries 640 00 '221 35
Incidentals \ 187 66 8 45
Building and grounds 17,443 60
Totals 1$ 19,932 66 $ 6,120 96 $
1,879 31
5,673 27
861 33
196 11
17,443 60
26,053 62
Tht Austin Dam
PLANT OPERATION.
37
Items. Water. Electric. Total.
Fixed salaries s 0,079 30$ 11,307 41$ 17,446 71
Temporary labor __ ___ 1 507 27 597 79 1,105 00
Fuel 7,018 40 15,180 24 22,804 04
Oil and waste 383 2S 591 83 975 11
Incidentals _ __ 209 94 212 04 481 98
Globes _ ... 18 32 18 32
Lamps 37 8G 37 80
Carbons _ ___ 15 72 15 72
Totals ^ 14,858 1 9 $ 28,027 211$ 42,885 40
P1 - ANT MA I NT K NANCE.
Electric. Total.
Machinery and equipment.. .. $ 498 03 $ 191 30$ 089 99
Fixed salaries 724 10 2,802 90 3,587 00
Temporary labor 2.911 70 2,705 37 5,077 13
Insurance 111 55 111 55 223 10
Other material 529 80 3 83 533 09
Incidentals 41)8 72 227 89 720 01
Totals $ 5,274 08$ 0,102 90$ 11,437 58
LINE EXTENSION.
Electric.
Total.
1,040 0l!$
105 51
220 10
0,903 95 __
113 98 ..
239 04 ..
739 52 ..
409 711$
3 80
808 95
18 70
1,820 25
1 ,207 73
2,013 15
209 33
2,049 72
109 37
1,035 05
0,903 95
113 98
239 04
739 52
18 70
1,820 25
1,207 73
2,013 15
209 33
10,028 11 $
1 ,028 77
7,211 08!
1.060 03
17,239 79
2,088 80
Temporary labor
Meters and fixtures
Incidentals
Pipe
Hydrants
Other material
Lamps
Poles
Wire
Transformers, etc
Cross arms-pins ...
Totals
Fixed salaries .
LINK OPERATIONS.
Fixed salaries $ 4,870 28$
Temporary labor --- 1,014 09
Incidentals l^ 77
Pipe - 94 42 _
Printing, stationery, etc 492 57
Globes 1
Carbons
Totals ... $ 0,057 73S
Total.
0,808 28 $
11,738 56
1 ,789 17
2,833 80
235 17
390 94
94 42
1,045 44
1,538 01
267 77
207 77
1,093 23
1,093 23
237 88(
237 88
11,530 94U
18,194 07
;58 Bulletin of the University of Texas
I.INE MAINTENANCE.
Items.
Fixed salaries
Temporary labor
Other material
Incidentals
Pipe
Fire hydrants
Valves
Meters, fixtures, etc
Damages and costs
Poles
Wire
Transformers and fixtures-
Cross arms, pins, etc
Totals
Water.
1,742 53 S
8,899 22
1,028 72 .
•137 35
6,596 67 .
103 53 .
453 49.
620 24
539 70
21,021 45$
Electric.
2,650 02 $
1,777 24
44 84
95 44
2,368 03
437 68
1,410 98
186 67
9,425 32 $
Total.
4,392 3b
10,676 46
1,628 72
891 77
6,596 67
103 53
453 49
665 08
635 14
2,368 03
437 68
1,410 98
186 67
30,446 77
SILTING ON LAKE MCDONALD.
In 1890 cross sections of Colorado River were taken at sixteen
stations, as shown in the tabular statement on page 40, Fig. 6.
The complete outline of the diagrams in Fig. 6 represents the
original cross section, the horizontal line being the water surface
even wdth the crest of the dam and the shaded area showing the
Fig-. 5. Map of Lake McDonald, Showing1 Locati on of Sections Where
Measurements for Silt Were Taken.
The Austin Dam
39
Fig. 6.—Cross section of Lake McDonald, illustrating accumulation
of sediment between 1S93 and 1S97 (illustrated by the lower shaded
area). The number above each section indicates its length, in feet.
40
1 inUciin of 1h< University of Texas
amount of silt that had been deposited up to February, 1900.
All vertical dimensions are exaggerated three times over the
horizontal dimensions. Cross sections were again taken for the
United States (Jeological Survey in May, 1897. also in January.
1900. The silt deposited from 1893 to 1897 is represented by
the lower shaded area, and that deposited from 1897 to 1900
by the upper shaded area.
The water tirst flowed over the crest of the dam on May 16,
1893, at which time there were 83,556,000 cubic yards of water
in the1 main channel of the lake up to the level of the crest of
the dam; in 1897 there were only 51,889,000 cubic yards of
water in the channel, the remaining 31,667,000 cubic yards (or
38 per cent of the original capacity) being silt. Estimated
in depths on a square-mile base we have, in 1893, a volume of
water equal to a depth of 80.9 feet, and in 1897, four years later,
we have a volume of water equal to a depth of 50 feet and silt
to a depth of 30.9 feet, showing the average amount of silt de¬
posited annually to be 7.7 feet, on a square-mile base.
The following table shows the maximum and mean depths of
water for 1893 and 1900, the maximum and mean depths of
silt for 1900, and the percentage of silting up at the respective
stations:
TABIjE SHOWING SILTING UP OP LAKE M 'DONALD.
Station.
Maximum depth
of water.
Maxi¬
mum
■ depth of
silt.
Mean depth
of water.
Mean
depth of
silt, 1900.
Amount
of silting
up to
Feb. ,1900
1893
1900
1893
1900
Miles
"Poet
Feet
I^eet
Feet
Feet
Feet
Per cent
0.0
66.0
39.0
27.0
40.1
27.5
12.0
31.2
0.2
67.0
38.0
27.7
37.(i
26.5
11.1
32.2
1.2
63.8
35.5
28.3
.39.6
21.7
S.9
30.0
3.0
56.0
31.5
24.5
.33.4
21.5
11.9
38 8
4.0
47.0
31.5
19.0
38.0
23.5
14.5
37.9
5.6 .
47.5
27.5
23.0
36.7
23.0
13.7
42.0
7.0
47.0
22.0
26.0
36.3
17.4
18.9
56.3
7.75
44.8
20.5
25.0
30.7
15.4
15.3
56.3
<>.25
40.4
13.4
29.0
30.8
10.2
20.6
66.9
10.4 _
40.9
13.5
27.4
27.2
7.9
19.3
71.8
13.7
29.4
9.8
26.0
29.3
5.5
14.8
78.9
14.6 __
24.0
12.5
16.0
17.2
9.0
8.2
50.4
15.9
16.6
12.0
15.0
13.2
10.0
3.2
60.0
17.4
13.3
9.5
7.0
11 .2
8.8
2.4
30.0
IS.9
7.6
5.0
2.6
5.6
3.9
1.7
33.0
20.0
3.7
2.2
1 .5
2.8
2.0
1.8
35.0
The maximum depth of silt is not always equal to the differ¬
ence between the maximum depth of water for 1893 and 1900
B. View of Dam Two Hours After Failure.
The Austin Dam
41
as the channel shifted at several points. This is very noticeable
at station 13.7, known as Santa Monica (or Sulphur) Spring
station. The last column ("Amount of silting up." etc.) gives
the ratio that the present cross section of silt bears to the original
cross section of water. Thus at Santa Monica Springs (station
13.7) 78.9 per cent of the original cross section has filled with
silt.
cumulation of sediment.
In February, 1900, there were 43,460,000 cubic yards of water
in the main channel of the lake beneath the level of the top
of the dam (equivalent to 42.1 feet on a square-mile base) and
38.8 feet of silt. Thus 48 per cent of the original storage ca¬
pacity of the lake was at that time mud. ITp to that date the
average rate of deposit, on a square-mile base, was 5.8 feet
per year.
In 1897 this silt, to within two miles of the head of the lake,
was a fine, impalpable, absolutely gritless deposit, .and where
newly exposed would not bear an appreciable weight on its sur¬
face. The writer has often tried its resistance all along the lake,
and an oar could be driven into it several feet.with moderate
pressure. Shovelfuls of it placed upon boards in a heaped-up
mass would immediately settle and spread so that the upper
surface was almost horizontal. A barrel of it, when first taken
up at Santa Monica Spring, soon spread out in a flat sheet. At
the head and for about two miles down the lake silt consisted
of a sand which readily deposited when the velocity of the
stream was checked by the waters of the lake. At occasional
points below the head of the lake small bars of sand were found
near the mouths of small canyons or creeks.
42
Bulletin of the University of Texas
From March 15 to April, 1899, the water level of the lake was
a little more than ten feet below the crest of the dam. The water
again commenced flowing over the crest of the dam on April 21,
and continued to flow over, at small depths, until June 7, when
the river rose to a height of 9.8 feet above the crest of the dam.
This flood continued until June 12, and its effect on the cross
section near the head .of the lake was marked. The section at
stations 14.6, 15.9, 17.4 and 18.9 were scoured out two to three
feet deeper than the sections of 1897, and at station 15.9, a sand
bar was deposited on the inside (left) of the curve of the river,
contracting the channel to less than half its former width.
The typical section illustrating the ratio of silt and water
areas for the whole lake is about midway between stations 5.6
and 7.0. i. e., about one-fourth of a mile below the Chautauqua
wharf. Fig. 7 illustrates this section, the vertical scale being
magnified ten times.
Fig. 5 shows the configuration and geography of the lake
formed by the dam. The river, as shown by Fig. 1, for two
hundred or three hundred miles, flows through a hilly country,
from above Colorado City, on the Texas and Pacific Railroad,
and in its course absorbs the water of the Concho, the San Saba,
the Llano, and the Pecan Bayou. All of the country drained
by these tributaries is hilly, with the exception of a few miles
along the head of the Colorado and the Concho.
When the break occurred the silt in the immediate vicinity
of the dam would have flowed out had there been no water. Just
above the part of the dam that gave way was a plateau whose
surface was on an average about eighteen feet below the crest of
the dam. At the time of the break the lake level was eleven feet
above the crest of the dam, making the depth of water on the
plateau twenty-nine feet. The torrent poured over this plateau
with immense velocity, as shown in PI. VI, A and B. The silt
on the plateau was cut away with such swiftness that in three
hours it was swept almost clean.
In the main channel the upper surface of the silt was thirty-
eight feet below the crest of the dam, giving, at the time of the
break, a depth of water in the main channel of 49 feet After
the water level dropped below the plateau the current was con¬
fined to a narrow gorge. A week after the failure the silt alon^
The Austin Darn
the shores of the former lake was cut into fantastic shapes by
the currents of the river and those of many mountain gorges.
The silt in contact with the dam undoubtedly increased the
pressure against it, but that portion of the dam across the main
channel where the silt was twenty-one feet deep and where the
pressure was greatest was on a good hard rock foundation and
successfully resisted it. There was practically no waterlogged
drift in this silt; the sounding indicated mud bottom. The silt
deposit kept the river at Austin muddy for months after the
failure.
For purpose of comparison, the silting up of reservoirs is
best reduced the heights and depths on a square-mile base. To
derive an expression for the amount of silt deposited in a given
time, let x equal depth, in feet of silt deposited in a year by
each foot of water in the reservoir. The depths of water are at
end of one, two, three, etc., in years:
First year, h-hx=h-h(l-x) ;
Second year, h(l-x)-h (1-x) x=li (1-x)2;
Third year, h (1-x) 2 -h (1-x) 2x=h (1-x)3;
Fourth year, h(l-x)3 -h(l-x)3 x=h(l-x)4.
Hence, if we let d=depth of water in n years, we have d=h
(l-x)u.
In 1897 h=81, d=50, n=4; x=0.1135.
In 1900 we have d=0.52h, n=62/*, (l-x)2%=0.42; x=0.09343.
For safety let us assume the least value of x; the following
table gives the results for each year on that assumption:
TABLES SHOWING SILTING UP OJF RESERVOIRS.
Years.
Amount
of
Years.
Amount of
Water, d
-h.
!l
Water, d—li
1
0.907
12
0.308
2
.822
13
.279
3
.745
14
.253
arc
15
,230
5
.012
16 -
.189
0
.555
17
.189
.171
6 2/3
.520
18
7
.503
19
.155
8
.450
20
.191
9
.414
25
.086
10
.375
Rf)
.053
11
.340
40
.020
These results will not be correct for any reservoir in which
there is an appreciable current acting on the bottom of the
basin, i. e., on the surface of the silt. In Lake McDonald the-
44
Bulletin of the I'Diversity of Texas
1
1—
...
wm
er
silt
/
Fig. 8.—Curve illustrating progress of silting in Lake McDonald
level of the water could sink to ten feet below the crest.
When this condition obtained, as it did during the months of
March, April, and October, 1899, there was a current on the
upper third of the lake. Unless the lake was drained by the
three three-foot pipes at the west end of the dam (which condi¬
tion did not occur after 1893), it was not possible for the current
under ordinary conditions to affect the silt in the lower two-
thirds of the lake. The results of the table are illustrated in
Fig. 9.
FAILURE OF THE DAM.
At Austin the Colorado emerges from a mountainous coun¬
try which extends for a distance of over two hundred miles in
a northwesterly direction. The channel above Austin is for the
most part a sinuous gorge held in by limestone mountains and
hills. Austin is at the foot of a long range of mountains, 37,000
square miles of which afford a drainage area for Colorado River.
The river is fed by the Pedernales, the Llano, the San Saba, the
Concho, and the Pecan Bayou. The configuration of the country
is such that the water runs off rapidly into streams.
Prom one p. m. on April 6 to four a. m. on April 7 there was
a rainiall of five inches at and in the vicinity of Austin, in a
mountainous country and on ground already wet, In addition
to this, tremendous rains fell all along the Colorado and its
tributaries from Austin as far as Llano, a distance of over one
hundred miles. The river rose rapidly, and by ten a m on
Saturday, April 7, it was apparent that the dam would be called
A. View Westerly Along- Line of Dam One Day After Failure.
B. Wreck of Power House.
The Austin Dam
4.1
upon to withstand the biggest flood since water first wetted its
crest on May 16, 189:1 At that hour the water level of the lake
was more than ten feet above the crest of the dam and it was
rising nearly two feet an hour. The greatest previous Hood
height occurred at nine p. in., on .June 7. ISO!), when the lake
level was 9.8 feet above the crest of the dam. The water had
then risen gradually throughout the day to its maximum level
of 9.8 feet. PI. TV, B, gives a view of the Hood of June 7, 1899,
taken when the lake level was 9.25 feet above the crest of the
dam and the water level only 22 inches lower than that of April
7, 1900; and PI. TV, A, is a reproduction of a snapshot, picture
taken with a small kodak five minutes before the dam broke. Tt
shows conclusively that there was no drift in concentrated
masses. Isolated logs and debris were passing, but they never
Plan of Dam and Power House.
Plan showing break in dam April 7, 1!)()(). AH is eastern
part (83 feet Ions on crest) left standing; AB and BC are portions of
dam first broken; xymn is dynamo room at power house; P is pump
room; L is point from which view shown in PI. VI, A, was taken; G
is point from which view shown in PT. VI, B, was taken; E is point
from which view shown in PI. IV, A, was taken; HS is bulkhead; B'
C' and D' A' are portions of dam that broke and disappeared forty-
five minutes after break; B' D' is the broken portion of the dam still
standing; M is point from which view shown in PI. VI, A, was taken.
At 11:20 a. m. on April 7, when the lake level had reached a
height of 11.07 feet above the crest of the dam, the dam gave way
at the point marked P> in Fig. 9, about three hundred feet from
the east end of the dam. Observers at E, F, and II all agree
4lj Built tin of the. University of Texas
in their testimony that it first opened at B, as though the mad
current had simply pushed its way through the structure. Sooner
than it takes to write these words the two sections, AB and BC,
each about two hundred and fifty feet long, were shoved or
pushed into the lower positions A'B' and B'C', about sixty
feet from their former positions in the dam. There was not the
slightest overturning. After the warning break at B, the water
over the part ABC was seen to rise several feet, and the next
instant the pent-up waters were pouring over the sections A'B'
and C'B'.
The view shown in PI. V, A, was taken at 11.23 a. m., or three
minutes after the failure. The parts may be identified by com¬
paring PI. Y, A, with Fig. 4 and with sketch plan, Fig. 9, the
view shown in PI. V, A, extending slightly beyond C in Fig. 9.
By 11:30 a. m. the lake level had fallen to the crest of the dam,
and the sections A'B' and B'C' were seen to be upright, each
still a solid mass, complete, unbroken, and intact, except for
the scaling off of the granite facing from the downstream face.
These sections now occupied a position practically parallel to
the dam, a view of which is shown in PI. Y, B, a snapshot taken
ten minutes after the break. To the casual observer the de¬
tached portions at this time had the appearance of having been
erected in their new positions by the original contractor. The
crests of the sections A'B' and B'C' were about on a level with
their original positions except at C, where the crest was slightly
higher, giving B'C' a slight longitudinal dip toward the power
house. Measuring along the crest the break left 456 feet, of the
dam (KC in Fig. 9). at the west end and 83 feet (AH) at the
east end. still standing unaffected.
As soon as the sections were broken out and moved to the
positions A'B" and B'C', the practically pent-up waters rushed
through the gap, those.held back by CK producing a strong cur¬
rent in the direction of the power house. This current struck
the wall of the power house almost on a level with the floor of
the pump room (about twelve feet below the crest of the dam)
crushed in all of the windows on the west side, flooded all of
the lower stories, and caught and drowned five employees and
three small boys. Two of the employees miraculously escaped
by climbing through a belt hole in the dynamo room fxymn
The Austin Dam
47
Fig. 9). These workmen were pumping water from the lower
portions of the power house.
At twelve o'clock, forty minutes after the break, the broken
section B'C' turned over toward the dam and disappeared be¬
neath the torrent, and the eastern end of the section A'B' was
broken up and engulfed. This left about one hundred feet
(B'D'), which was shifted slightly out of its parallel position.
This section (B'D') was cracked from the crest as far down as
could be seen. Some time during Saturday night the smallest
portion of this one hundred-foot section was swept away. The
picture reproduced in PI. VI, B, was taken from the top of the
bulkhead at two p. m. on Saturday, April 7.
At 12.05 a. m., Sunday, April 8, the northern two-thirds
(xymn, Fig. 9) of the west wall of the power house gave way
and fell, taking with it the roof over the dynamo room and
wrecking the corresponding part of the east wall. The power
house was 198 feet by 54 feet, and had a total height on the
river side of 112 feet.
The walls were of brick, except the first twenty feet, which
were constructed of dressed granite rock about 21/1 feet by 3
feet. The dynamo floor (xymn, Fig. 9) was about on a level with
the crest of the dam. The floor of this room extended as a gal¬
lery over the pump room (P) in which the big duplex pumps
were located.
The broken sections moved back about 60 feet and the toe
rested on the shore line of the tail-race. The impact and the
resultant compressive stress on the stones on the curved face
tore the granite facing loose from the core in several places.
The section was stripped of its facing stones in the third course
from the top as far down as could be seen, a distance of fully
thirty feet. Some of the top granite stones of the section were
loosened in their beds by the break and were carried away by
the current.
Specimens of the cement of the core have been examined and
these have been found to be first-class in every particular. In
some places breaks occurred through limestone rubble and the
adhering cement, showing that the strength of the joint was
superior to that of the limestone. The behavior of the granite
facing indicates very clearly that it was easily pulled oft' by the
4S
I'ullttin of llt< lTnivcrs\tij of Texas
immense forces brought into play. The impact cracked the sec¬
tion along' an irregular surface about forty-two feet below the
crest. There was not sufficient continuity between the rubble
core and the granite facing. There were slight irregularities
in the line of contact between the granite and the rubble, but
when subjected to the powerful forces of the water pressure
the two separated at many places. In a few cases isolated gran¬
ite blocks 011 the curved crest were forced from their beds.
The maximum depth of the water near the dam was only
38 feet below the crest. Thus at the time of the break the total
depth was a little more than 49 feet. The lake had silted up
from the original bed-rock bottom in the main stream exactly
30 feet. Had there been no silt a much larger volume of water
would have passed and the results would have been more disas¬
trous at and below the dam. While this silt would flow, it was
sluggish and served to retard the current, thus prolonging the
flood several hours (it actually continued, with great velocity,
for nearly two days). Within twenty-four hours the river level
had fallen more than forty feet, but this only served to confine
the flood to the main channel, with little diminution of velocity.
At 3.20 p. m., four hours after the dam broke, the water level
had dropped 30 feet and was at the high-water mark of the
old channel, cutting the banks both above and below the dam.
Below the dam the alluvial banks reached a height of 64 feet
above the toe of the dam. This whole mass was in a few hours
cut back 40 feet. The effect of this is considered under the
heading "Silting up of Lake McDonald," page 38.
It is almost certain that the dam failed by sliding. It seems
that at a point three to four hundred feet from the east end
the limestone upon which the dam rested was of a friable na¬
ture. Mr. Frizell realized this, and it was stated to be a part
of his plan, had he continued in charge of the work, to re-enforce
the bottom of the river just below the dam by a cement founda¬
tion about one hundred feet wide by six hundred feet Ion"1; it
was also contrary to his purpose to have the water of the tailrace
run along the toe of the dam.
In order to ascertain whether any of the foundation of the
dam remains in the broken gap, soundings were made in June
and in the latter part of October. 1900. Three lines (A B and
B. Broken Dam Showing" in Foreground. Sand Bar Left in Main Channel.
Tht Austin Dam
4!)
Cj of soundings were made parallel 1<> the upper face of the
dam, namely, at 2, 16.5, and 42 feet respectively, from the upper
face. A cord was tapped every twenty feet, and the soundings
were made with a sharpened three-fourths-inch iron rod. Sta¬
tions were taken west to east. The following table shows the
result of the soundings, the depth being measured from the
crest of the dam. When the October soundings were mg|e the
water surface was 56.1 feet below the crest of the dam. The rod
soundings were added to this to give the depth recorded in the
table.
RESULT OF SOUNDINGS TAKEN AT AUSTIN DAM SITE IN
JUNE AND OCTOBER, 1900.
Station.
Line A.
Line B.
Line O.
Depth in
Eeet.
Bottom.
Depth in
Feet.
Bottom.
Depth in
Feet.
Bottom.
60
Dam
edge
40
63.1
20 -
67.9
0
Water's
Dam
Water's
Dam
68.4
Mud
edge
edge
20
73.5
Solid rock
69.1
Solid rock
69.5
Solid rock
40
69.5
Solid rock
69.1
Solid rock
70.1
Solid rock
60
69.9
Solid rock
70.1
Solid rock
70.9
Solid rock
80
70.6
Solid rock
71.1
Solid rock
71.3
Solid rock
100
71.1
Solid rock
72.6
Solid rock
72.5
Solid rock
120
72.3
Solid rock
72.6
Solid rock
72.4
Solid rock
140
a72.6
Solid rock
72,9
Solid rock
72.6
Solid rock
160
a72.3
Solid rock
73.1
Solid rock
72.5
Solid rock
180
a71.9
Solid rock
72.1
Solid rock
73.1
Solid rock
240
a68.1
Solid rock
68.9
Solid rock
69.6
Solid rock
200
a71.3
Solid rock
71.1
Solid rock
71.3
Sand
220
a70.9
Solid rock
60.1
Solid rock
71.0
Rock
260
67.1
Mud
68.1
Gravel
280
63.6
Gravel
67.9
Mud
300 —
Water's
63.1
Gravel
Loose rock
320
Water's
edge
If we remember that the height of the dam above the rock\
bed of the river was 66 feet, and that the foundation was not
(except as noted on the next page by Mr. E. W (} roves), even
with its toehold, more than 68 feet below the crest, a ulanee at
the foregoing table will convince anyone that 110 part of the
foundation in the western three lmnderd feet of the broken sec
tion remains. From the present ordinary eastern water's edge
a large sand bank extends along the entire eastern section still
remaining. Soundings were not made through this thirty-loot
sand bank, but the crest of the big section of the dam, shown in
all the views of this broken part, is only four feet lower than the
crest of the portion standing, which fact indicates very clearly
4-164
50
Bulletin of the University of Texas
that its foundation went with it, as it is resting practically in the
old tail race, whose hed was lower than the bed of the dam.
Tn all seventy-four soundings were made, and sixty-seven of
these show that the depth of bed rock is over eight feet below
"low water," and at the other seven soundings the rod could not
he driven through the sand, mud, or gravel, to solid rock. At
no place was any solid rock encountered as near as eight feet
to the "low water" mark in the area of soundings, which cov¬
ered a space of 18,000 square feet.
The condition of the foundation, the detached standing sec¬
tion B'D', Fi«r. 9), and the condition and position of the other
broken section that occupied the gap that disappeared soon after
the break, all preclude the theory that the dam broke at the
level where it was thirty-one feet in thickness. This level
was twenty-five feet above "low water" and thirty-five feet
below the crest. If it had broken on this level, then there was
a section only thirty-five feet high that broke off and moved back.
The broken sections moved down the stream about sixty or sev¬
enty feet, and rested in a position practically parallel to their
original positions and in the tail race of the dam, the bottom
of which was lower than the foundation of the dam. If the dam
had broken at the level of thirty-five feet above "low water,"
then when the upper thirty-five feet of the dam moved off three
things Avon Id have occurred: (1) The upper part Avould have
turned over as it slid off of the lower part, Avhich it did not do.
This is shown by the section B'D', still standing (PI. VII, A),
and by the other section Avhich was carried bodily doAvnstream
and which remained upright forty minutes after the first break.
(2) When the thirty-five-foot section moved doAvn stream, if
by any possible means it. could have slid off, then fallen a dis¬
tance of thirty feet and landed in the tail race in an upright posi¬
tion, its crest Avould have been thirty feet beloAV the crest of the
standing portion. All this is disproved by the facts. The crest
of the standing section (PI. VII, A) is only four feet (instead of
thirty) loAver than the original crest, and that of the portion
Avhicli stood for a while Avas as high as or higher than the orig¬
inal crest. (3) The crest of the standing section is now fifty
feet above ordinary Aoav, Avliereas it would have been onlv about
twenty-two if the dam had broken at the tAventv-five foot level
The Austin Dam
above low water. (4) That section of the dam carried down¬
stream and still standing can be examined and the twenty-five
foot level will be found actually intact. The position of these
sections, horizontal and upright, indicates that the cause of the
failure was a sliding out bodily on its base of that portion that
failed.
On April 8, 1896 (four years before the dam failed), in a
letter to the Mayor, Mr. Frizell called attention to the fact that
dangerous abrasions might occur near the point mentioned^i e.,
three to four hundred feet from the east end. The waters of
the tailrace followed the toe of the dam fully six hunclerd feet
and were discharged through a section forty-five feet wide. This
section had an average depth of 2.8 feet during the day, and
about three feet at night when the full power was on. In March,
1899, the writer, with Mr. II. K. Seltzer, made soundings along
the toe of the dam between this narrow neck and the power
house. At or near the point where the break occurred the bot¬
tom was not reached with a rod 5.3 feet long, even when the hand
holding it was thrust at least two feet below the surface. The
water surface of the tailrace was then 2.5 feet below the toe
of the dam. This makes the bottom of the tailrace more than
9.5 feet below the top of the toe of the dam. The tailrace near
the dam passed over a shoal-like formation and entered the tail-
race pond about fifty feet from the east end of the dam. Be¬
tween this point and the narrow neck alluded to the tailrace
was bounded by the toe of the dam and an elliptical shore line.
Its maximum width was 125 feet, its narrowest width (at the
neck) forty-five feet. It was at this neck that many measure¬
ments of the flow were made during 1888 and .1889 for the
United States Geological Survey. In March, 189!), simultaneous
measurements were made of the tailrace at this neck and of the
fore-bav. While the flow through the tailrace exceeded that in the
fore-bay, the difference was not greater than could be accounted
for by the fluctuations of flow caused by increased demands
on the street car service. Early in 1899, when the lake level
was ten feet below the crest of the dam, the writer urged some
of the authorities to shut off all power some night at twelve
o'clock, and after the tailrace water had run off to have the
flow measured in order to ascertain the leakage, if any; but
Bulletin of lh< (J>tiv< r.sif// of T< .ras
there were difficulties which prevented the stopping of the works.
It is probable that there was no leak under the dam from the lake.
Water from the lake going under trie dam would have been
under a head of sixty-six feet, and would have emerged with
a velocity of more than sixty-four feet per second, which would
have cut a way the limestone foundation in a few hours.
~\Ir. E. AV. (Jroves, who was connected-with the work, as an
engineer, from the preliminary surveys to the completion of the
dam, ^tates, that for the first one hundred and fifty feet from
the cast bluff very good rock was found: that at that point a
fault of seventy-five feet was encountered, in which there was
no semblance of stratified rock, most of the material being adobe
or pulverized rock, with an occasional streak of red clay: that
the excavation in Ibis space was carried down eight or ten feet
in the upstream trench, and the trench widened from four feet
to ten or fifleen feet; that the fault extended to an indefinite
depth; that from the west edge of the fault the foundation rock
was poor for three hunderd and fifty feet, and that supple¬
mentary protection was added to the upstream side opposite
the fault by dumping clay along the face of the dam.
The limestone formation in the vicinity of the dam consisted
of alternately hard and soft strata. The outcropping in Bee
Creek (just above the dam\ that at Taylor's lime chute (about
Fig. 10. Cross section showing undermining of (oe of dam
a half mile above the dam), that through which the excavation
was made to repair the head-gate masonry are all of that
character. The soft strata could be handled with a piek and
Tin A us/iit Dam
often with a shovel, but the hard strata were composed of a
fairly good quality of limestone. In its western part the dam
rested on one of these hard strata. During a freshet in 1892
the overfall cut through these hard strata, tore up large pieces
(some of them ten feci long, four feet wide, and 2.5 feet thick
and seven and eight tons in weight), and deposited a whole
quarry in a confused and irregular pile about one hundred and
fifty to two hundred yards farther down the river. These; stones
remained in that location until the big freshet of June 7, 181)9,
when they were carried away.
The foregoing facts arc necessary for a proper understanding
of what follows. In 1897, Mr. J. (J. Palm, one of Austin's
leading citizens and a cashier of the oldest national bank in the
city, while fishing along the toe of the dam, ran his fishing pole
under the toe for a distance of six feet. This shows conclusively
that either the water flowing along the tailrace had scoured out.
the foundation under the toe of the dam or the overfalling
water had undermined it. A large percentage of the water
flowing over the east half of the dam at ordinary height rein¬
forced the tailrace waters and produced a strong current along
the toe of the dam for more than half of its length. It has now
been proved, by actual measurements, that the toe was cut under
at some place, as shown in Fig. 10. In speaking about the mat¬
ter Mr. Palm said that he often wondered why the toe did not
break off. This undermining of the toe left the dam exposed
to the pressure of the water, and it became only a question of
which was the stronger—the water or the friction between the
dam and its bed.
In regard to geological formations, the following is quoted
form a letter of Mr. Robert T. Hill, of the United States Geologi¬
cal Survey, in the Engineering News of May H, 1900:
"In the plateau country, which begins about a mile above
the present site of the dam. the strata are firm and horizontal, and
the river flows over ledges of firm and solid rock, which would
have made a suitable and durable foundation for the construc¬
tion. Just below this point, within a belt of country upon which
the dam is located, the strata are excessively jointed and faulted,
constituting what is technically known as the Balcones fault zone.
The geological formation is also different, consisting of the
54
Bulletin of the University of Texas
limestones of the Edwards formation, which are exceedingly
porous and soluble, while to the west of the fault zone the strata
are less soluble and more durable. The action of the subterranean
waters upon the Edwards limestone results in dissolving it into
caverns and crumbling strata, even where its surface appears
perfectly solid and durable. Furthermore, artesian springs of
great volume and pressure well up in the joint planes and fis¬
sures in this formation. The site of the dam chosen crossed
one of ttie most conspicuous fault lines, at the northern (east¬
ern) end of which, after the excavation and construction had
well advanced, a spring of this character mentioned developed
which greatly endangered the tie-on at the end and cost many
thousands of dollars to circumvent. * * * Had the dam been
located less than two miles above the ])resent site, this structural
condition would have been avoided."
A second geological consideration in the construction of the
dam, and one to which sufficient attention was not, in my opinion,
paid, was in the choice of material. Within sixty miles of Aus¬
tin by rail are some of the most superb granite quarries in the
world. This material was used to face the dam, but its center
was built of the same soluble limestone as that previously men¬
tioned, which was obtained from a quarry at the mouth of
Bee creek on the south (west) side of the river, less than half
a mile from the dam. An examination of the face of the quarry
shows the character of the material taken from it for use in
the dam, and a glance is sufficient to show that its solubility
was such as to render it utterly untrustworthy.
On account of the immense importance of the Austin dam as
an engineering structure—it being the largest in the world
across a flowing stream— the writer here submits the opinion
of some of the engineers who were connected with it from time
to time.
Mi-. Frizell lias said that the location at Mormon Falls, two
miles above the chosen site, presented points of decided superi¬
ority ovei the locality selected, but the board of public works
thought the location inconsistent with the purposes of improve¬
ment. Mr. Frizell does not consider that the solubility of the
rock had any bearing on the failure, and sees no reason lo doubt
that the immediate cause was the undermining on the down-
The Austin Bam
55
stream side, caused by the abrasive action of the current and
the constant stream of water coming from the power house
and flowing along the toe of the dam on its way to the open chan¬
nel of the river. A progressive weakening is attested by the fact
that during the preceding year the dam had withstood a flood
substantially as great as the one in which it failed. The toe of the
dam, which was left without support by the undermining, con¬
tained granite blocks of more than six tons weight.
It is on record that the breaking clown of this unsupported toe was
imminent, in which event each of these stones would become a mill¬
stone _ (propelled in such a flood by some 2000 horsepower) in the work
of grinding the friable rock bottom and extending the undermining.
At the wooden dam across the Connecticut River at Holyoke, Mass., an
action of this kind became threatening in 1866. A pit 20 feet deep
had formed on the downstream side of the dam. This danger was
met by the construction of a massive apron of cribwork filled with
stone, which prolonged the duration of the structure more than
thirty years, or until the construction of the present stone dam. At
Austin the engineer had in contemplation from the beginning an
analogous work, namely, an extension of the massive apron by a
bed of concrete, to be applied as soon as the abrasive action had made
sufficient progress to indicate the character and extent of the work re¬
quired for its suppression.
X. Werenskiold, one of the engineers of construction, in a
letter to a friend in the latter part of 1900, said:
There can be no doubt that the failure was not caused by any de
fective work in the dam itself, but by the entire body being pushed
downstream and broken from the lateral pressure on account of too
small frictional resistance under the dam. It is also proven con¬
clusively that this resistance against sliding had been materially
-diminished by erosion below the toe of the dam, and to that extent
the failure is chargeable to the lack of care in maintenance.
I have no doubt but that all the masonry went, or slid, and I am
inclined to the belief that some of the rock ledges underneath went
with it. 1 think it possible that the foundation might have been
good enough for a dam without overfall, but it proved not to be
good enough for this bold structure. 1 think it probable also that
vibrations of the dam, caused by the fall of the water, may have
had a very detrimental effect on the underlying foundation and also
increased the lateral pressure of the silt and earth against the dam
far beyond the generally assumed water pressure, until this lateral
pressure overcame the combined bonding resistance on the dam proper,
together with the frictional resistance under the base.
As early as May, 1893, in reply to a direct question from one of
the leading members of the board, [ stated that the foundation under
the east end of the dam was not what it should be; that it was hard
to say whether it was safe or not, but that I thought that the dirt
filling against the dam on the water side would prevent undermining
and save the structure. I also suggested the necessity of close
watching below the dam.
On May 7. 1894, when replying to a letter from another of the
leading members of the board, I suggested that they make borings
.)()
Hnlhtin of /he I'nivrrsil tj of Texas
below the dam for the purpose of ascertaining the necessity of taking
some precautions for the safety of the dam, stating that there might
or there might not be immediate necessity for so doing, but that I be¬
lieved it would prove necessary in the course of time. In another part
of the same letter I suggested concrete or paving in front of the power
house. From this you will know that they were not without friendly
warnings.
But in spite of all this I can not say that the works were designed
and built with due safety or precautions, or that, to my knowledge,
proper borings and examinations of the underlying foundations were
ever made.
Mr. J. T. Fanning remarks as follows:
The theoretical stability of the niasonrj of the dam in its normal con¬
dition, as completed in 1893, was sufficient to resist a much greater
volume of flood How than the flood at the time of the break. The struct¬
ure substantiates this view in the fact that the westerly part of the
dam, nearly one-half its length, resisted the force that broke out the
mid section. It is evident that there was a large surplus of resist¬
ance, both as to sliding and overturning, in the remaining part of the
structure, as otherwise the moving sections would have pulled with
them those portions of the dam now standing erect in place.
Undercutting.-—That there was undercutting of the toe of the dam
at a point where the dam first yielded is attested by soundings made
before the sliding of a portion of the dam.
A writer in public print has attributed this undercutting in large
part to the flowing of the tail water from the water wheels in the
power house along the toe of the dam toward the channel, as shown
in PI. I, A. This theory is not sustained by the facts.
This dam was built on the rock bed of an ancient channel of a great
river. Both ancient shores are of rock and nearly vertical to the
height of the dam. When the dam was constructed the modern river
occupied less than half the ancient river channel, and the remainder
of the channel, covering somewhat more than its easterly half, was
occupied by an alluvial deposit forty to sixty feet in depth. A narrow
cut was made through this deposit to the east shore for placing the
foundations of the dam in that part of the ancient channel. The tail-
water from the power house flowed out through this cut on bed rock
to the modern west channel, as shown in PI. I, A, and had the toe
of the dam for its right shore and the earth deposit for the other
shore.
In examining the theory of the bed rock cutting by the tail-water
alone we observe that the quantity of tail-water flow was ordinarily
about 250 cubic feet per second and in the narrowest part of the chan¬
nel had a velocity of about two feet per second. In the wide section
of this channel, at point of scour, the tail-water alone had a mean
velocity less than three-tenths foot per. second. The theory of scour
and undercutting of the rock by the tail-water flowing at these low
velocities is absurdly erroneous.
The undercutting was probably not done by the scour of extreme
floods. It was anticipated that the cutting by floods would be at a
distance from the toe of the dam. PI. I, A, shows that the flood passed
over a space in front of the toe of the dam and did their cutting of
the alluvial deposit below the line of the lower end of the nower hm^p
about 200 feet from the toe of the dam.
When the flood glides down any sloping face on the lower side of a
dam its current is discharged under the backwater below the dam
somewhat as shown in Fig. 11. When logs pass over a sloping dam
The Austin Dam
> i
——>71
jMw
riCTEE 11
Fanning's Illustration of Plow of Water Over Austin Dam.
with the flood they first appear at tlie surface of the ebullition at some
distance below the dam, as at m, in Fig. 11, and then return aloim
the surface toward the dam. The greater the flood depth on the crest
the farther from the toe of the dam do the logs appear and the more
swiftly the logs return with the surface current toward the dam.
Breakwater.—In a case such as is shown in Fig. 11 tlie breakwater
comes in contact with only the toe of the dam. With eleven feet depth
on the crest, sixty feet fall, and twenty-five feet oi backwater, the dis¬
charge velocity past be/ is great. The water at d then flows back
over the swift undercurrent with a velocity due to the free head of
backwater next the dam, but at its surface level can not reach the
dam. These effects of flow, which may be observed at many dams,
seem to have been overlooked by most writers on the subject. It is
illustrated in part by PI. IV, B, in which the valley between th»
downflowing stream and the returning current is filled with spray.
Fig. 11 is a reproduction of a sketch relating to these matters ex¬
plained by the writer to members of the board of public works at
Austin, in June, 1S92, when he first visited the works. The founda¬
tions of the dam were then in place and the superstructure in progress.
In computing the stability of a masonry dam, the weight of water
resultants from a to b, Fig. 11, have usually been neglected. So, also,
have the reactions of the tail-water aginst the dam throughout the
flowing jet, and also the weight of reactions at b c and the weight of
the water at d, which in this case are sufficient to materially enhance
the factor of safety.
Fall at the toe.—Referring again to the undercutting at the to«
of the dam, which occurred at a point about l>00 feet from the easterly
abutment, we call attention to the appearance of the low and moderate
flows at the fall over the toe of the dam, as shown in PI. I, A, and
PI. I, B. This fall should but slowly cut hard limestone, but might
cut such soft stone as was said to have been found at the point men¬
tioned. At the right of Fig. 11 is a sketch suggesting the possible
effect of such fall on a soft rock or adobe stratum. A fall of one foot
to surface of breakwater gives a velocity of about eight feet per
58
Bulletin of the University of Texas
second, and of two feet a velocity of about 11.34 feet per second, and of
two and one-half feet, as observed, a velocity of about >2.68 feet per
second, each independent of the velocity acquired down the slope.
The failure of the dam was attributable to a local weakness in the
rock on which it rested, it is probable that the friable or soft stratum
under part of the dam which first moved, and which was not removed
and replaced, became so saturated with water that upward pressure
from the pond was transferred to the underside of the dam in suffi¬
cient amount to neutralize a considerable part of the weight pressure
of the masonry resting upon that soft rock and, furthermore, that
this saturated stratum became like a lubricant on which that part
of the dam had but moderate resistance against sliding.
The parted sections constituted nearly one-half the length of the
dam. It is probable that the section of the dam resting on the for¬
mation on which it had not sufficient frictional resistance was held
as part of the beam until the vertical cross crack came at the central
part of the soft section at B (Fig. 9), and also that then the two parts
adjacent to B were Held briefly as cantilevers until they cracked at
C and A, after which they slid, moving swiftly faster at B, the point
of first crack, until they rested SO feet forward of their original posi¬
tions. The erosion in front of the toe of the dam was not so wide
but that the two parted sections of the dam slid over the erosion with¬
out tilting and stood erect in their new position, as shown in PI. VI,
A.
In such constructions it is usual to countersink the toe of the dam
flush into the bed rock, giving it an abutment, which makes sliding
impossible.
Power house foiaiclatioiis.—The injury to the powTer house was a
remarkable and unprecedented accident.
The foundations remain now uninjured, as indicated in Fig. 9. The
basement windows were placed above the forty-foot backwater level
and the river wall was trussed to resist the inward pressure of forty feet
of breakwater. The wave of water from the broken dam rose above
the windows and broke them in and then flooded the basement where
the turbines were located. As the flood receded the basement held
this water, as a tank, up to the forty-foot level. When the back¬
water outside had next da;v (twelve hours after break in dam) fallen
below the level of the basement floor the inclosed water pressed part
of the basement wall outward and permitted part of the floors and
roof to fall.
Site of pacer house.—Some one has stated that the power house was
in more danger from the flow over the dam than it would have been
if located one hundred feet farther downstream. Its position as con¬
structed was adopted as the one of greatest safety and stability, and also
in part because the extension of the abutment and steel penstocks one
hundred feet farther would have added $20,000 to their cost. The rela¬
tive location of the dam and power house are approximately shown in
Fig. 9. Tn this sketch GF is the face of the east abutment, but with ex¬
aggerated curve. This easy curve of the abutment was proportioned
with care to deflect the flood current in a predetermined direction so
that it could not scour along the face of the power house founda¬
tion except as a return eddy. The return eddy flowing upstream
would be weakest near the dam, so that part of the foundation nearest
the dam was safest of all from scour by flood. The foundations of the
power house were uninjured by the rush of waters dashed against the
building.
Mr. Wilbur F. Poster, of Nashville, Term., upon invitation
Tht: Austin Dam
of the committe appointed by the water and light commission
to consider the ways and means of rebuilding the dam, after
visiting Austin and examining the dam site, submitted the fol¬
lowing report:
Any estimate of this kind, in the absence of definite plans and speci¬
fications which are to be complied with, is at best uncertain and un¬
satisfactory; and in this case it has been assumed that those which
controlled the original construction would be followed in the renewal,
in order to preserve uniformity of appearance of the entire dam when
completed, but with such modifications, to secure stability and for the
sake of economy, as are herein suggested for your consideration.
The report herewith submitted is from the standpoint of a builder,
guided by some experience in construction of similar work in other
localities and from information obtained in your city as to various
details of cost, and will, therefore, ignore technical questions as to
cause and manner of failure, etc., which have been so ably and ex¬
haustively discussed by well-informed and intelligent observers who
have given much time to the study of the facts. Only the conditions
as they now exist will be considered.
The engineering problems involved demand the most painstaking,
careful investigation, and these you will doubtless submit to some mem¬
ber of that profession in whom you have entire confidence, and whose
advice, plans, and specifications, when once adopted, as well as his
instructions with regard to details during the progress of the work,
you will rigidly abide by. I may be pardoned for suggesting that some
of the questions thus to be most carefully studied in the light of the
unfortunate experience you have had are:
(1) Whether it will not be better to abandon entirely the present
location, and in rebuilding adopt one by which you will avoid the
"faults" or unreliable strata in the geological formation which seems
to have been the prime cause of the trouble you have had, both with
the foundation of the dam and the construction of your bulkhead
masonry and power house. Of course, a large amount of material will
be available by salvage from the old dam when removed and from the
debris from the portion destroyed.
The surveys, soundings, and careful investigations already made by
the eminent professional gentlemen who have been connected with
your work heretofore will greatly facilitate the decision of this point.
(2) Whether, in view of the observed action of the overflow in time
of flood, a modification of the profile or cross section of your dam is not
advisable, wherever it may be built, the upstream face to be battered
or offset in lieu of vertical, and the downstream face to have flatter
slope, thus increasing the weight of the mass and giving a larger
frictional area upon the base.
(3) A careful consideration of the merits of the fossiliferous lime¬
stone, which is abundant in the vicinity of the dam, as a buildng ma-
teral. It does not seem reasonable that stone which has withstood
the action of the elements for untold ages should be condemned as al¬
together worthless. In view of the excessive cost of granite, both in
quarry cost and transportation, as given to me in Austin, I believe
that the limestone of the vicinity should be used in the upstream face,
at least to a point fourteen feet below the crest of the dam, and quite
possibly on a portion of the downstream face also, and that it will be
reliable for strength and durability in that portion.
Assuming that these and other details will hereafter be decided by
your engineer, I will endeavor to answer, as briefly as possible, the
It nil/tin of the ('tun rsilij of Texas
inquiry of Mr. Caswell, guided by my personal examination of the
locality and by my best judgment as to the cost of the various items.
It might be assumed by some that inasmuch as the total length of
the dam between abutments is 1,091 feet and its total cost was about
$611,000, and as about 01 feet at the east end and 500 at the west end
remain standing, that the interval r>oo feet could be replaced for its
pro rata of the total, or about $300,000. This supposition will be found
erroneous for several reasons:
(1) The shattered condition of Ihe 01 feet now standing at the east
end makes its removal and reconstruction a necessity, and inasmuch
as this is at a place where a very troublesome leak occurred after com¬
pletion of the dam, it is probable that the foundation itself ought to be
excavated to greater depth.
(2) A large mass of the original dam is still standing, just far
enough downstream from its original position to be very much in the
way of construction of new work, and must be removed.
(Y) A very large deposit of earth and silt east of the present chan¬
nel, also along the toe of the dam on the west side of the channel, must
be removed for construction of new work.
(4) An examination by sounding with an iron rod reveals the
fact that the bed rock in the channel through which the river is now
flowing is an irregular surface, ranging from 8.6 to 12.6 feet below
the assumed low-water line, which was the top of the toe of the dam
as built. This is the result of seven soundings, and is pretty con¬
clusive proof thai noc only the foundation stone is gone from this
portion of the dam, but that the bed rock itself has been broken up
and washed out to a depth in some places of more than 6 feet. The
average of these soundings is 10.8 feet, and while it is not certain
that this condition extends to the eastern end of the gap, yet it will
not be safe to estimate otherwise, as it is probable that if not washed
out at least that much would have to be removed before rebuilding.
This break-up of the bed rock I have assumed to be from a point
6 feet above the upper face of the dam, a line 20 feet below the toe.
This, then, will make a pit 48:J feet long by 02 feet wide by 4.8 feet
deep which must be filled with masonry or concrete before reaching
the base of the original dam.
(5) It seems to me imperatively necessary that the toe of the dam
its entire length should be protected by an apron of masonry or
concrete to prevent undermining. This r have estimated as 1,100
feet long, average width 20 feet, average depth 3 feet.
(6) In my estimate I assumed that the upstream face wall will
be built of limestone to a height 14 feet below the crest of the dam
and will have a slope or batter of 3 inches to 1 foot vertical.. This
will add 442 feet to the original sectional area of the dam, making
it 2,642 feet. The upper 14 feet of the upstream face, the coping,
and the downstream face all to be of granite, as in original plans All
this will be shown more fully by the sketch (fig. 12) which I here¬
with inclose, showing suggester profile. It is suggested that the
entile filling oi interioi shall consist of concrete made of American
or Portland cement.
(7) The cost of the contractor's plant or outfit under conditions
like these is quite as great for the construction of a dam 600 feet
long as for the original length of 1,001 feet.
With the above explanations 1 submit the following estimate o*
Earth excavation, wet and dry, 21,000 cubic yards, 30 cents $6 °00
Rock excavation, 2,000 cubic yards, $1.60, $3,200. ''
Removal of masonry now standing, 14.000 cubic yards $l $14 000
The Austin Dam
til
Granite coping course, 1,373 cubic yards, $19, $26,087.
Granite facing, downstream, 5,535 cubic yards, $11.75, $65,036.25.
Granite facing, upstream, 684 cubic yards, $11.50, $7,866.
Coursed limestone masonry, upstream face, 4,738 cubic yards, $7.50,
$35,535.
Concrete filling, 55,749 cubic yards, $5.50, $306,619.50.
Total, $464,643.75.
Deduct for salvage of granite in old dam and debris, 3,025 yards,
$7, $21,175.
Total net, $443,468.75.
in the above estimate it is assumed that the granite work can be
done at the same prices as in the original contract, notwithstanding
the increased figures given me when in Austin. It is also assumed
that all the work will be laid in American Portland cement mortar
of approved quality.
Incidentally, while at the site of the dam, I made a measurement
of the flow of the stream, which was said to be at a stage lower
than for many years. This measurement, which was of the rudest
type and without any facilities for securing accuracy, indicated a
flow of 360 cubic feet per second. I also examined the ground on the
west side of the river and found that by cutting a channel 100 feet
wide, with an average depth of about 50 feet, and approximately
1,000 feet long from the canyon of Bee Creek southwardly to a ravine
which empties several hundred feet below the dam, a spillway might
be obtained, which, with 10 feet of water on the dam, would pass
a volume of water equivalent to 1 foot over the crest of the dam.
The excavation would be solid rock, would probably cost $150,000,
and is only mentioned as my attention was directed to the matter.
In this report I have made no attempt to determine the extent or
estimate the cost of work to be done in reconstruction of the power
house. Whether the head-gate masonry must be rebuilt, whether the
FIGURE 12
roster's Sug-g-ested Cross-Section for Rebuilding- Austin Dam.
In conclusion. I would say that the estimate herewith furnished is
concurred in by my business partner, Mr. R. T. Creighton, who was
present and assisted in all the examinations and measurements.
HiiIIiHh of ilu (> invP-rsitji of Texas
penstocks and turbines should be lowered, whether two or three pen¬
stocks will not be sufficient in lieu of six, and whether the river
wall of the power house should be more solidly rebuilt are questions
that can be best decided by those who are familiar with all the de¬
tails and who know the present condition of the plant and the cost
of all the items involved.
One detail, however, should not be overlooked or neglected in any
event. The tail race, by which water is discharged from the tur¬
bines, should be so directed that the current will not scour along the
toe of the dam, thus endangering its stability, however carefully it
may be protected.
It will be observed that Mr. Foster concludes from his sound¬
ings that not only the foundation stone but part of the bed rock
was torn up and washed away. It will be remembered that
Superintendent II. C. Patterson, in a report to the Water and
Light Commision in July, 1900, said that "the original founda¬
tions were in no way damaged, and in all eases not less than
six feet of the footing coures remained." The writer has made
many soundings at the dam, the results of which have been con¬
firmed by Mr. Foster's report.
Since the failure of the Austin dam the city has been operat¬
ing its waterworks, electric light plant, and other motors for
commercial purposes with steam power. Beaumont oil and lig¬
nite have been u>ed as a fuel for part of the time. The fuel bill,
with the cleaning of boilers, has sometimes amount to about
$60,000 per year. This represents in round numbers the amount
that the water power was saving the city per year. The most
economical plan upon which the dam could be rebuilt would
be to design a waterpower plan to utilize the ordinary tlow of the
river, and to add an auxiliary steam plant of a capacity equal
to the power that would be generated by an amount of water
represented by the difference between the low ordinary flow and
the minimum flow. In the face of the present fuel bills the re¬
building of the dam becomes an imperative economic and public
necessity.
EYAXS'S EE POUT.
In September, 11)05, Oeorge E. Evans, Civil Engineer, of Bos¬
ton, Mass., was sent by Stone and Webster to investigate the
condition of the dam and to report upon the feasibility and cost
of rebuilding the same. On arriving in Austin Mr. Evans called
upon the writer, who nave him every assistance possible. While
the Oily of Austin had no records, drawings or notes 1 he writer
The Austin Dam
63
placed all his data at Mr. Evans's disposal. On account of its
importance, Mr. Evans's report is here published in full.
In regard to Mr. Evans's report, the writer wishes to remark:
1. That all estimates of the flow of the Colorado were taken
from the writer's report to the TT. S. Geological Survey, which
was published in "Water Supply Paper. No. 40 (Austin Dam),
in Water Supply Paper, No. 105 (Water Powers of Texas) or
in later annual reports. Mr. Evans' remarks that "The flow
has been measured and found as low as 180 cu. ft. per second."
That statement was true when Mr. Evans wrote the report in
1905, but new flow data have been obtained since that date,
which renders this statement inaccurate. The flow of the Colo¬
rado River at the dam site from August 15 to August 25, 1910,
was only twenty second-feet, which would have generated one
hundred and four (104) horse powers at most.
Boston, Mass., October 30, 1905.
Messrs. Stone d- Webster, 84 State Street, Boston, Mass.
Gentlemen : At your request I visited Austin, Texas. The latter
part of September, 1905, for the purpose of making an examination
of the site of the Austin dam and an estimate of the cost of rebuilding
the same.
I expected the city would have plans of the original dam and power
plant, but was disappointed by not finding a single plan and the city
officials did not know of any, and all that 1 have to guide me are the
measurements that 1 made on the ground. Four lines of soundings were
made from the east shore of the river to the east end of the west sec¬
tion of the dam. which is now standing. The soundings were taken
from a raft, held by ropes from either shore. A steel rod was driven
through the deposit of mud and sand to the ledge. From previous
soundings taken at the same places, as nearly as possible, it appears
that some of the foundation had been washed away.
dam.
The Austin dam was built across the Colorado River about three
miles northwest from the city of Austin. On April 7, 1900, about 500
feet of the central portion was washed away, when the water on the
crest of the dam had reached a height of 11.07 feet. Undoubtedly the
location was not the best that could have been found, and, according
to geologists, the foundation is limestone and chalk and the dam was
located sub-parallel to one of the most conspicuous fault lfnes. The
stratification is inclined slightly down the river. Its length between
abutments was 1090.25 feet, measured on the crest. It varied in height,
above the foundation, from 66 feet to 70 feet and the base meas¬
ured 66 feet, including the apron or toe. It was mostly built of
limestone and chalk, which was quarried nearby. The upstream and
downstream faces of the dam were built of excellent granite, which
was brought by rail from Granite Mountain, to the site of the dam, a
distance of about seventy-five miles. The granite facing had not
headers of sufficient length to bond properly with the body of the dam,
and is more like a veneer. On the west side of the river, there remains
Hulhtin of the University of Texas
of the original dam about 4!)1 feet (crest measured 4G0.5 feet), which
appears to be uninjured, except possibly a small portion of the down¬
stream granite face at the cast end which may have to be relaid.
At the east side, there is a section of the dam, about 103 feet in length
(crest measurement Ml feet), the most of which will have to be taken
down, because there are two large cracks in the upstream face ex¬
tending from the crest lo I he ground line. The westerly end of this
section (12r> feet from east end of dam) was moved down stream ten
inches and al a point 7:! feet from the east end the dam is in its
original position. Portland cement mortar mixed in the proportion
of one part cement and three parts of sand was used for laying the
stones throughout the whole dam. The three courses of the toe are
doweled and clamped together.
. As the west section has withstood the pressure of two large freshets,
f should recommend that this portion be utilized, but in making a de¬
sign for rebuilding the dam 1 have considered it economical to in¬
crease the cross-section so as to insure against future floods, which
might be greater than the one which wrecked the dam, and as this
part of the foundalion is known not (o lie as firm as the portion under
the west section which remained, it will have more weight, and there¬
fore more friction on its base to withstand the pressure of the water.
Without any borings into the ledge foundation, 1 have considered it
best to assume that a trench masonry wall from six to eight feet below
I he base of the dam might be necessary to cut off water from passing
under the dam.
Assuming twelve feet of water on dam, the line of resistance comes
well within the middle third, when the weight of the masonry is as¬
sumed to average 13."> pounds per cubic foot. The original shape of
the crest has been kepi more for the appearance than' for strength,
but the straight slope below is not as steep, and where the new and
old sections join will form a warped surface. The upstream face is
perpendicular as in the original design.
Abutments, about fifteen feet in height should be built at each end
of the crest so as to prevent a vacuum forming under the overflow
water. There are three ;!G-inch pipes with valves laid through the west
end of the dam at an elevation of 16..r> feet above toe of dam.
FOREBAY.
During the year 1S!)0 the water in the lake was ten feet or more be¬
low the crest of the dam for a period of seventy-two days. As this
condition is liable to occur again, and also because this portion of
the foundation caused the most trouble and the masonry was washed
out during construction (causing an additional expense of nearly
$-'1.o00). this foundation should be thoroughly examined and made
sate to build upon. I have considered it best to recommend the re¬
building of the forebay, and to reduce the size of the penstocks to
eight feet in diameter and only provide for six. In the original de¬
sign it w:cs laid out for nine 9-foot penstocks, only seven were laid.
These penstocks are in poor condition, being badly pitted by rust and
out of shape; No. ■< measures nine feet eight inches horizontal, and
eight feet, one inch in vertical diameter. One of the penstocks has
its top dented downward eight or ten inches and appears as though a
lar^e stone was dropped on it when being covered with earth. The
old penstocks were placed so high a person told me that he had seen
less than two feet oi water flowing through them. Tt is proposed to
place the bottom of the S-foot penstocks at elevation forty-one, or nine-
een feet below the crest of the dam, which will insure the top being
covered during a low stage of the river.
The Austin Dam
65
COLORADO K1VEH.
Before work on this plant was commenced, it was estimated that the
low waterflow was 1000 cubic feet per second, which would produce
continuously over 5000 horsepower, but since then Ihe flow has been
measured and found to be as low as ISO cubic feet per second. This
river rises in Dawson county, in the western part of Texas, and has
a drainage of about 37,000 square miles. No records of the rainfall
have been kept on this area. The average rainfall at Austin from 1856
to 1899 has been 32.5 inches, not including 1882-3-4. In IS56 the mini
mum was 19.6 inches and the maximum, in .1874, was 46.5 inches. An
average rainfall of twenty inches per year on the drainage area is
considered a fair estimate. The maximum, minimum, and mean dis¬
charge of the river at Austin, since January, 1S96, is as follows (this
does not include the flow of Barton Creek, which enters below the
dam) :
discharge jx cubic feet per second.
Year.
18!X5
18! >7
1897
l.!>00
1!H11
1002
1!KK
i x in n 1111.
.Minimum.
Mean
11 ,oo<>
180
1 100
11,000
200
I'M 10
20,000
210
1880
103,400
ISO
1170
1 2:1.000
■III)
:u 15
40,!'12
175
I'M
:;l ,250
ISO
2224
:!2, 500
:;20
i:;oo
If the years 1900 and 1903 are omitted the average minimum flaw
is 187 cubic feet per second.
There is such a wide range between the maximum and minimum
flow of the river that a large amount of the water runs to waste, and
the only way to utilize the power it to reservoir some of the larger
tributaries.
Without examining the country, 1 believe favorable locations could
be found where rock filled dams of moderate heights could be built
quickly and at a small cost. Only a small amount of concrete masonry
would be required for the top of the dam, at the spillways and for cut¬
off walls.
SILTS.
On May 16, 1903, the water first flowed over the dam, and the lake
at that time was estimated to contain over 2,253,000,000 cubic, feet of
water below the level of the crest. In February 1900, it was estimated
there were 1,173,000,000 cubic feet. Thus in seven years 48 per cent of
the original storage capacity of the lake had been filled with alluvial
deposit. Tn four years the deposit had reached a point nearly nine¬
teen miles above the dam. Taking into consideration the rapid silting
up of the lake and the probability of impairing the storage capacity of
the lake, I would recommend the placing of four gales 4 x S, to b^
operated by electrical or hydraulic power, near the bottom of Ih^ chan¬
nel, for the purpose of washing out the mud. The mud could be stirred
up by a screw or some other device, operated from a small tug boat
WATER POWKK.
When selecting the amount of power to be installed the minimum
flow or the average maximum flow of the river should be taken. A
flow of 180 cubic feet per second and 55 feet head would give 900
horse power at 80 per cent efficiency. The mean average flow from
1896 to 1903, omitting 1900-3. on account of the unusually large flows.
tit; Bxll< iiii of ihe University of Texas
is 1 487 cubic feet per second. This amount under a head of 50 feet
would give 6 800 horse power at 80 per cent efficiency. I have con¬
sidered four pairs of 21 wheels best adapted to the present conditions,
which would give nearly 2,700 horsepower at 75 per cent efficiency,
and these should be supplemented by a steam plant of half the above
power There are two extra penstocks provided for further develop¬
ment. Upon a careful examination of the 27 wheels now half buried in
the sand, it may be found that they could be used to advantage. The
old water wheels have been partly buried in sand and mud for the last
five and one-half years, and the Piatt Iron Works company that in¬
stalled the wheels, writes that it would probably be less expensive to
put in new wheels than to attempt to repair them.
Deposit to the depth of about twenty-eight feet has been washed into
the power house basement and onto the area on the west side.
POWER HOUSE.
The original power house was 54 x 198 feet and built of brick. The
southerly portion is still standing and has an interior dimension of
40.5 x 8*0.5 feet. On the west or river side it is 112 feet high and on
the east or front side it is thirty-two feet high. (The glass is broken
out but the walls appear to be in good condition.)
A brick end would have to be built at the north side. This room
would probably be large enough for some time to come, because the
water wheels would be located in the basement and the generators in
i lie upper story would be driven by wire ropes. The generators can
not be placed lower than an elevation of 50, because freshets have
reached the following unusual heights; March, 1852, 36 feet; July, 1869,
43 feet.; October, 1870, 36 feet; June, 1S99, 23 feet; April, 1900, 45 feet.
[These are guesses by the "oldest inhabitant."—T. U. T.]
In the basement there would be four pairs of 21-inch wheels (giving
670 horsepower under a 50 foot head and 75 per cent efficiency per pair),
and above in the second story there would be three direct generators
of 300 kilowatts each, one 150 kilowatt alternating generator, exciter,
switchboards, etc.
It will be necessary to build an engine and coal house at the east
side of the present power house and install two 1000 horse power
boilers and a 1000 horse power compound engine, with its necessary
appurtenances. By the use of a jack shaft the engine can drive two
of the larger generators and probably the water wheel can take care
of the small generator. The coal or oil (for fuel) can be brought to
the station by the present railroad.
REMARKS.
Before any work of construction is commenced a thorough survey
should be made and borings taken across the river at the site and also
some above and below the dam, and from these data an estimate of
the cost could be made reasonably accurate. Although the following
estimate is only approximate and made from limited data, I believe
that it is large enough to put the plant into operation. The approxi¬
mate estimate is as follows:
12,000 yards earth excavation $ 2,400 00
2;<,000 yards earth excavation 13',800 00
6,500 yards rock excavation 9,100 00
18,000 yards removing old dam 18^000 00
10,300 yards granite . facing 164,800 00
•>41,500 yards rubble concrete 282 500 00
1,200 pounds wrought iron 1*296 00
Wix penstocks, 8 feet diam., 24 feet long 3 360 00
The Austin Dam
(57
Six gates and hoists
Four sluice gates
Engineering and contingencies
$3,000 00
7,100 00
64,S00 00
Total
$ 742,000 00
Respectfully submitted,
(Signed) Geo. E. Evans.
PROPOSITION OF CONSOLIDATED CONSTRUCTION
COMPANY.
In 1907 the Consolidated Construction Company was granted
a franchise by the City Council and the "Water and Light Com¬
mission to construct and maintain a dam at or near the old site
on the Coloi'ado River, subject to the following general condi¬
tions :
1. The company was granted right to erect, own and main¬
tain a dam and accessories and to overflow certain lands for
forty years.
2. The height of dam to he equal to that of the old dam
if built in the old location. If built further up the stream it
was to be as much higher as the natural rise in the river.
3. The company was to deposit $25,000.00 in care of the
City Treasurer as a guarantee of good faith, which was to be
forfeited if the company failed to expend $100,000.00 within
the first year after the acceptance of the contract. The power
house was to be completed within two years within date of ac¬
ceptance. when it was to be occupied by the city for its exclu¬
sive use and control.
4. The headgate masonry was to be sufficiently high to pre¬
vent inflow into the power house, and these headgates were to
he kept in repair, free drom leakage and seepage by the com¬
pany.
5. In event of the total or partial destruction of the dam,
etc.. or in the event of occurrence of leaks to the extent of
twenty-five per cent of a natural flow of the river the annual
payments were to cease until repairs were made.
6. The company was to have the use of all material in
dam, headgates and power house except metal work, together
with all plans, specifications, maps, drawing and engineers'
reports which it then had or might thereafter possess.
7. In case a new site was selected the city was to secure and
<18
Bulletin of the University of Texas
pay for the land and overflow rights, while the company was
to build the power house.
S. The city was to keep-the buildings used in connection
with the plant in repair while the company was to keep in re¬
pair the dam, forebay. headgates and headgate masonry. The
city was to pay for the rent of the buildings and for the water-
power developed from a natural flow of the river and from
storage the sum of $65,000.00 annually for forty years.
9. The city obligated itself to pay said annual payments
from the revenues arising from the operation of the Water,
Light and Power Plant, and further agreed that no taxes
should be levied for this purpose, and the company was to look
alone to the earnings of the plant for the payment of this $65,-
000.00 per year.
10. The company agreed to pay $1.75 for a day's labor of
eight hours to workmen employed on the property.
11. The city agreed to pay all taxes levied or assessed
against the property mentioned in the contract.
12. The company agreed to secure the city during the life
of the contract against loss or injury to the dam, headgate,
power house and machinery caused by breakage, leakage or
seepage through, around or under the dam.
13. The company agreed not to assign the contract to any
person, firm, or corporation other than J. Gr. White & Co.
14. The city reserved the right to have penstocks placed
at a depth and position to be selected.
15. The city agreed to begin the installation of machinery
as soon as the power house was completed and to be ready for
operation within six months from the date of completion of the
power house.
1'). The city agrees not to operate its steam plant except
when the water power was not sufficient to meet the require¬
ments of the city or its patrons.
17. The company has the right to inspect the books of the
W ater, Light and Power Company Department of the city.
18. Tln> city agreed not to grant franchises or privileges to
any electric light or power company for services to the city and
its inhabitants during the life of the contract.
1!'. All notices to the company were to be made in writing
Till Austin Dam
lilt
signed by the Mayor or Chief Executive of the ciry. addressed
to the collecting; agency of Hie city.
20. In case the city complied with all the privileges of the
contract, the dam and appurtenances were to revert to the city
at the end of the forty years.
21. In case of default by the company or its assigns for a
period of two years, it was to forfeit all rights and privileges
under the contract and the city was to assume control and pos¬
session of the property covered by the contract.
22. The city was granted the right to purchase the dam and
appurtenant property at any time after ten years by discounting
the remaining annual premiums at 6 per cent.
23. The company was to provide sluice gates or drain pipes
near the bottom of the dam.
24. The company was to indemnify the city against all dam¬
ages caused by the breaking of the dam, headgates, etc.
25. Arbitration clause, contract to be approved by the City
Council and by the "Water, Light and Power Commission.
27. All ordinances or parts thereof in conflict wtih the
franchise were repealed.
BORINGS AT THE DAM.
During the spring and summer of 1908 the city of Austin had
26 borings made at the dam site. The work was under the super¬
vision of W. G. Kirkpatrick and A. C. Blanton, the latter having
immediate direction. The location of these borings is shown
in Fig. 13, while their elevation is shown to small scale in
Fig. 14. The cores for all these borings were preserved
and laid out in relative position both longitudinally and verti¬
cally for the inspection of the Board of the Government Engi¬
neers when they met in Austin at the request of the Mayor to
report upon the feasibility of replacing the dam. This work was
the most important and valuable that the city of Austin has ever
undertaken in connection with the dam, and, the money expended
is practically the only money that was ever spent for gathering,
•collecting, and systematizing valuable data upon which re¬
ports could be based. Had the city spent as much money in
making borings before the dam was located, it" would have saved
over half a million dollars at the very least, and had the city
spent as much as $2000 in obtaining and collecting necessary
hydrographic data, it would have returned a thousand fold on
the outlay. The writer wishes to go on record once and for all
Bulletin of the University of Texas
The Austin Dam
71
in approving' the outlay for making the borings at the dam site.
On account of the very great importance of these borings the
log of all the 26 holes is here published in full.
""[Note.—The water shown in Fig. 14 under the words "top of
water," is on upstream side of dam instead of downstream side
as indicated.]
holj-: xo. 1.
Top of Hole 20.5 Feet Above Crest of Dam.
Feet from Surface.
To
7.00
10.00
10.50
12.00
15.00
16.00
20.00
25.00
26.00
27.00
30.75
31.00
33.00
37.33
37.50
41.00
42.00
44.00
45.00
46.50
47.00
55.00
55.00
58.00
63.00
65.00
68.50
73.00
78.00
79.50
85.00
Thickness of
Strata in
Feet.
7.00
3.00
.50
1.50
3.00
1.00
4.00
5.00
1.00
1.00
3.75
.25
2.00
4.33
.17
3.50
1.00
2.00
1.00
1.50
.50
6.00
2.00
3.00
5.00
2.00
3.50
4.50
5.00
1.50
5.50
Material.
Sand, rock and clay.
Clay and broken ledge.
Limestone.
Broken limestone.
Limestone.
Cavity.
Limestone.
Chalky honeycomb limestone.
ICavity.
Chalky limestone.
!Limestone core.
'Cavity.
Limestone core.
Chalky limestone.
Washed rods down.
Chalky limestone.
[Chalky limestone.
(Limestone core.
jChalky limestone.
;Soft limestone.
Hard limestone.
[Very soft limestone.
Hard limestone.
Very hard limestone, all core.
[Hard limestone.
Very soft limestone.
Soft limestone.
Very soft limestone.
Limestone core.
,Flint and limestone core.
Hard limestone.
HOLE NO. 2.
Top of Hole 14.50 Below Crest of Dam.
Feet from Surface.
From To
Thickness of
Strata in
Feet.
Material.
0.
2.00
2.00
Soil.
2.00
2.60
.60
Concrete.
2.60
7.33
4.73
Soft limestone.
7.33
8.00
.67
Hard limestone.
8.00
9.50
1.50
Flint.
9.50
15.50
6.00
Hard limestone.
15.50
16.17
.67
Soft, limestone.
16.17
16.67
.50
Hard granite.
16.67
16.83
.17
Cement.
16.83
18.67
1.83
Hard granite.
18.67
19.00
.33
Cement.
10.00
20.50
1.50
Granite and cement.
20.50
23.50
3.00
Granite, cement and limestone
23.50
32.50
9.00
Hard limestone.
32.50
47.00
14.50
Limestone.
47.00
53.67
6.67
Soft limestone.
53.67
51.17
.50
Flint.
54.33
60.00
1 5.67
Soft limestone.
60.00
100.00
40.00
Limestone.
Bulletin of the University of Texas
The Austin Bam
73
HOLE NO. 3.
Top of Hole 11.0 Feet Below Crest of Dam.
Feet from Surface.
I 1
Thickness of
Strata in
Material.
From 1 To
Feet.
0.
7.00
17.00
17.50
18.00
33.00
35.00
38.83
30.00
7.00
17.00
17.50
18.00
33.00
35.00
38.83
39.00
40.00
7.00
10.00
.50
.50
15.00
2.00
3.83
.17
1.00
Sand.
Olay, gravel and boulders.
Hard limestone.
Soft limestone.
Hard limestone.
Soft limestone.
Limestone.
Flint.
Limestone.
HOLE NO. 4.
Top of Hole 43.50 feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in
Material.
From
To
Feet.
0.
3.00
3.00
Clay.
3.00
12.00
9.00
Clay and rock.
12.00
22.00
10.00
Clav, rock and boulders.
22.00
23.50
1.50
Soft limestone.
23.50
23.67
.17
Hard limestone.
23.67
27.00
3.33
Soft limestone.
27.00
27.50
.50
Hard limestone.
27.50
28.50
1.00
Soft limestone.
28.50
36.00
7.50
Hard limestone.
HOLE NO. 5.
Top of Hole 30.0 Eeet Below Crest of Dam.
Feet from Surface.
i Thickness of
-j Strata in
Material.
From
To
Feet.
0.
4.00
1 4.00
Clay and rock.
4.00
31.60
27.60
Sand, clav and
rock.
31.60
:-f6.00
4.40
Hard limestone
HOLE NO. <;.
Top of Hole 41.0 Eeet Below Crest of Dam.
Feet from Surface.
From
0.
21.00
22.00
29.00
31.75
32.25
To
21.00
22.00
20.00
31.75
32.25
100.00
Thickness of
Strata in
Feet.
21.00
1.00
7.00
2.75
.50
6 7.75
Material.
Sand, clay and boulders.
Boulders.
Clay and boulders.
Sand and boulders.
Hard limestone,
j Limestone.
74 Bulletin of the University of Texas
hole xo. 7.
Top of Hole 40.0 Feet Below Crest of Dam.
Feet from Surfaee.
Thickness of
Strata in
Material.
From
1
To
Feet.
0.
14.00
14.00
Sand, clay and boulders.
14.00
31.00
17.00
4 1/2 in. sand pipe, rocks, clay and sand.
31.00
37.00
6.00
3 in. casing through clay boulders and
sand.
.37.00
38.00
1.00
Put down 1 ft. of :: in. easing through
broken ledge.
38.00
47.00
9.00
Limestone.
47.00
60.00
13. (K)
Hard limestone.
60.00
65.00
5.00
Limestone.
HOLE NO. 8.
Top of Hole 40.75 Feet Below Crest of Dam.
Feet
from
Surface.
Thickness of
1
_
Strata in
.Material.
From
To
Feet.
0.
29.75
29.75
Sand, clay and boulders.
29.75
36.75
7.00
Hard limestone.
36.75
39.75
3.00
Very soft limestone.
39.75
44.15
4.40
Hard limestone.
(4.15
45.15
1.00
Soft limestone.
45.15
46.75
1.60
Sand and clay.
40.75
47.75
1.00
Soft limestone.
47.75
52.75
5.00
Hard limestone.
52.75
53.75
! .00
Soft limestone.
53.75
59.50
5.75
'Hard limestone.
HOLE
\<>. 9.
Top of Hole 44.25 Feet Below Crest of Dam.
Feet
from
Surface.
Thickness of
— —
Strata in
.Material.
From
|
To
Feet.
0.
10.00
10.00
Sand.
10.00
26.00
16.00
Red clay and gravel.
26.00
32.67
6.67
Sand, clay and boulders.
32.67
37.00
4.33
Hard limestone.
37.00
41.25
4.25
Hard broken limestone
41.25
43.00
1 .75
('avity.
43.00
49.00
6.00
Hard limestone.
49.00
55.00
6.00
Limestone.
HOLE NO. K).
Top of Hole 63.50 Feet
Below Crest of Dam.
Feet
from
Surface.
Thickness of
_ —
Strata in
Material.
From
|.
To
Feet.
0.
3.50
3.50
Water.
3.50
8.40
4.90
Sand and clay.
8.40
16.00
7.60
Limestone.
16.00
25.00
9.00
Hard limestone.
25.00
27,00
2.00
Cavities and soft limestone.
27.00
28.75
1 .75
Hard broken limestone.
The Austin Dam
HOLE NO. 11.
Top of Hole 66.25 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in Material.
Feet.
From
To
0.
O.OO
9.50
10.00
6.00
9.50
10.00
80.00
6.00 Water.
3.50 Sand and clay.
.50 Sand and limestone.
70.00 Limestone.
HOLE XO. 12.
Top of Hole 70.50 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in
Material.
From
To
Feet.
0.
10.00
10.00
Water.
10.00
14.00
4.00
Sand.
14.00
36.00
22.00
Limestone.
HOLE NO. 13.
Top of Hole 73.75 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in
Material.
From
To
Feet.
0.
13.00
13.00
Water.
13.00
17.00
4.00
Limestone.
17.00
19.00
2.00
Water rose two feet.
19.00
19.50
.50
Limestone.
19.50
38.00
18.50
Hard broken limestone.
HOLE NO. 14.
Top of Hole 68.90 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in
Material.
From
To
Feet.
0.
10.00
10.00
Water.
10.00
13.50
3.50
Sand and gravel.
13.50
14.50
1.00
Concrete and limestone.
14.50
14.75
.25
Limestone.
14.75
16.00
1.25
Sand and clay.
16.00
19.50
3.50
Sand and boulders.
19.50
39.00
19.50
Limestone.
HOLE NO. 15.
Top of Hole 00.75 Feet Below Crest of Dam.
Feet from
Surface.
Thickness of
Strata in
Feet.
Material.
From
To
0.
13.50
15.00
13.50
15.00
35.00
13.50
1 .50
20.00
Water,
(.ravel and
Limestone.
sand.
7<;
Bulletin of the Ir)i.ivcrsil)/ of Texas
HOLE NO. 16.
Top of Hole 72.50 Feet Below Crest of Dam.
Feet from Surface.
From
0.
11.00
10.00
To
11.00
16.00
35.00
Thickness of
Strata in
Feet.
Material.
11.00 Water.
5.00 Sand and boulders.
10.00 Limestone.
HOLE NO. 17.
Top of Hole 73.50 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in
Material.
From
To 'Feet.
0.
14.00
14.67
14.00 14.00 Water.
14.67 .67 Chopped 4 1/2 in. pipe, limestone.
40.00 25.33 Limestone.
HOLE NO. 18.
Top of Hole 71 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in Material.
Feet.
From
To
0.
11.00
11.00
40.00
11.00 Water.
29.00 Limestone.
HOLE NO. 10.
Top of Hole 68 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in Material.
Feet.
From
To
8S
O 00 00
8.00 8.00 Water.
8.50 . 50 Chopped sand pipe in limestone.
40.00 31.50 Limestone.
HOLE NO. 20.
Top of Hole 68.15 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in Material.
Feet.
From
To
0.
8.00
14.00
8.00
14.00
50.00
8.00 ;Water.
6.00 i Flint and limestone.
36.00 (Limestone.
■
The Austin Dam
HOLE NO. 21.
Top of Hole 68.75 Feet Below Crest of Dam.
Feet from Surface.
Thickness of I
Strata in
Feet.
Material.
From | To
0. 8.67
8.67 12.00
12.00 30.00
8.67 Water.
3.33 {Limestone.
27.00 jLimestone.
HOLE NO. 22.
Top of Hole 68.75 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in
Material.
From
To
Feet.
0.
8.50
8.50
Water.
8.50
14.00
5.50
Limestone.
14.00
33.00
19.00
Limestone.
33.00
39.00
6.00
Limestone.
HOLE NO. 23.
Top of Hole -18 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in
Material.
From
To
Feet.
0.
4.00
4.(10
Large boulders and sand.
4.00
16.00
12.00
Sand and boulders.
16.00
17.50
1.50
Limestone and flint.
17.50
55.00
37..50
Limestone.
HOLE NO. 24.
Top of Hole 43.25 Feet Below Crest of Dam.
Feet from Surface.
From j To
Thickness of
Strata in
Feet.
Material.
0.
7.00
7.00
Sand, clay and old concrete filling-.
7.00
23.00
16.00
Sand, clay and wood.
23.00
26.50
3.50
Limestone.
26.50
39.00
12.50
Hard broken limestone.
39.00
60.00
21.00
Limestone.
HOLE NO. 25.
Top of Hole 4.2 Feet Below Crest of Dam.
Feet from Surface.
Thickness of
Strata in
Feet.
Material.
From
To
0.
4.00
22.25
28.00
38.00
51.50
80.00
109.00
131.00
4.00
22.25
28.00
38.00
51.50
80.00
109.00
131.00
150.00
4.00
18.25
5.75
10.00
13.50
28.50
29.00
22.00
19.00
Sand pit.
Sand boulders and clay.
Hard broken limestone.
Hard limestone.
Limestone.
Limestone.
Limestone with hard bands.
Limestone.
Limestone.
Bullctii) of the IIDiversity of Texas
HOLE NO. 20.
Top of Hole "hi.50 Feet Above Crest of Dam.
From
Feet from Surface.
To
Thickness of
Strata in
Feet.
Material.
3.00
0.00
10.00
15.00
18.00
28.50
HI .00
0.
3.00
0.00
10.00
15,00
18.00
28.50
31.00
34.00
3.00 Pit broken limestone.
3.00 Very liairl limestone. •
4.00 Hard broken limestone.
5.00 Limestone.
3.00 Limestone, clay rods washed down.
10.50 Broken limestone.
2.50 Soft limestone.
3.00 Soft limestone washed down with weight
oi rous.
S.OO Hard limestone.
5.00 Hard limestone.
5.00 Very soft limestone.
of rods.
34.00
42.00
47.00
52.00
52.50
58.00
02.00
04.00
82.00
42.00
47.00
52.00
52.50
58.00
02.00
01.00
82.00
230.00
50 Very hard limestone.
REPORT OF1 GOVERNMENT ENGINEERS.
During- the summer of 1908 Mayor Frank M. Maddox re¬
quested the director of the IT. S. Reclamation Service to appoint
a hoard of government engineers to investigate and report upon
the feasibility of rebuilding the dam. The following hoard was
appointed: Arthur P. Davis, Chief Engineer of the IT. S. Re¬
clamation Service. Louis 0. Hill, Reclamation Engineer in charge
of the Roosevelt Dam, and T. IT. Taylor, Dean of the Depart¬
ment of Engineering of the University of Texas. The Mayor
requested the engineers to advise the city of Austin upon the
following points:
1. Advise as to the feasibility of replacing the dam.
2. If the present site is considered feasible, advise as to
the best and most practicable plan for rebuilding. Go into
detail as far as your board deem necessary.
3. Advise without going into minute detail the approximate
cost of replacing the dam in accordance with the general plans
suggested.
4. Should you deem the present site impracticable, then ad¬
vise as to other site with approximate cost.
The Board spent several days in an examination of the struc¬
ture of the geological formation between the dam and Mt. Bon-
nell, inspected the exhaustive series of borings executed by W.
G. Kirkpatrick and A. C. Blanton, and finally made the follow-
Tin Austin Dam
79
ing ^commendations in regard to the old dam if the city should
decide 1o rebuild it:
1- Provide a deep curtain wall near the upstream face to
cut off percolation under the dam, so far as possible in order
to reduce upward pressure to the minimum.
2. Increase the mass of the dam, and thus increase its re¬
sistance to sliding, and such increase should be so located as to
utilize the pressure of water on the dam, so far as possible.
3. Repair the foundation of the toe of the dam with good
monolithic reinforced concrete and carry it down into natural
rock so as to secure its resistance to sliding and protect it against
future erosion.
All these precautions should be employed if the dam is rebuilt
at the old site. We have prepared preliminary drawings illus¬
trating in general the above idea as applied to repair of the re¬
maining portion of the old dam and the construction of the new
portion.
After the new dam is placed in service, care must be taken
to prevent erosion of the toe from any cause, and frequent ex¬
aminations taken against its repetition.
The curtain wall should be about six feet in thickness, and
connected by steel rods to the main dam. It should be carried
to depths to be determined by local conditions as work proceeds,
but in general to elevation 400 to 410 or to depth of twenty to
thirty feet below original heel of the dam. It should go below
any cavities disclosed by borings or otherwise.
The east abutment and bulkhead are on very poor foundation,
and should be entirely rebuilt, carrying the base below the cavi¬
ties and leakes that have developed.
The body of the new portion (Fig. 15) of the dam should be
built of concrete with good hard stones embedded in it. forming
what is called "rubble concrete."
For the sake of appearance the granite facing on the lower
slope should be placed according to the loimei plan. I his hov-
ever, is not necessary on the back of the dam where it will be
concealed by water, though the Granite should be used for a dis¬
tance of about ten feet below the crest, where the back will be
uncovered in times of protracted drouth, the remaining portion
of the back of the dam being concrete.
There is little value in the old works except the masonry now
SO Bulletin of the University of Texas
Fig. 15.
standing in the western half of the river, where stand about
five hundred feet of the original dam, which needs extensive
repair and protection to insure its safety. The penstocks are
gone with rust, and have buckled and warped under their ex¬
cessive loads of earth.
The power house is so far wrecked and the remaining portion
is so poorly adapted to future requirements as to be of little
use except to furnish material for new construction. In plan¬
ning the power house provision should be made for the installa¬
tion of about five thousand liorse-power eventually which can
advantageously be employed in connection with steam auxiliary.
For the present we have assumed about three thousand horse¬
power will be required to have included its installation in our
Fig. 16.
The Austin Dam
81
The following preliminary estimates have been made of the
probable cost of rebuilding the dam and power plant at the
present site. These estimates should be used with great caution
as the foundation especially at and below the line of the toe has
been eroded to an unknown depth, and we have to depend largely
upon assumptions regarding the necessary yardage in the founda¬
tion and toe of the dam. The quantity of necessary ovc.avat.ion
and concrete for the curtain wall is also very uncertain ''spe¬
cially at the eastern end. It has, therefore, been necessary to
make assumptions on this point. Owing to local conditions
these uncertainties can not be entirely cleared up until con¬
struction is in progress.
ESTIMATED COST OF REPLACING AUSTIN DAM AND THE POWER HOUSE.
Rock excavation for cut-off wall, 8(XX) cubic yards, at $3 per cubic yard $24,00<) 00
Concrete in cut-off wall, !*XX) yards at $6 per cubic yard .54,(MX) 00
Excavation for dam to wall and apron, 80,000 yards, at 75 cents per cubic
yard J 60,000 oo
Reinforced concrete in toe wall and apron 40,000 yards at $0 per yard $ 240,000.00
Concrete and facing in main dam 74,000 yards at sj'6 per cubic yard 444,000 00
Excavation for east abutment 3,500 yards at $2 per cubic yard 7,000 00
Concrete wall under bulkhead, 3,500 yards at $<> per cubic yard 21,000 (X?
Sluice gates 5,(XX) (X)
Power house and three units 200,000 0<)
$1,055,000 00
Engineering and contingencies, 15 per cent. 158,500 00
$1,213,500 00
The site of the old dam is very undesirable. It is direct!v
across a zone of geographical faults and the river bed is faulted
for nearly two miles above the dam site. It will be impossible
to prevent percolation under the foundation of the dam. The
amount of such percolation is purely conjectural, and would
not only entail a loss of valuable water, but would be to some
extent a menace to the safety of the dam.
The rock in the foundation is soft and very irregular. If
there were no property at this site, we would not regard it as
within the realm of consideration. We have accordingly examined
the canyon above, and find that a much better site exists at Mt.
Bonnell, about two and one-fourth miles above the old site,
where the rock is much harder, and where so far as now known,
no geologic faults exist at or above the dam site. The length of
the structure is about the same. No borings have been made here,
so no accurate estimate of cost can be made at present. Prom
• i rough approximate based upon all the information now at
hand, we are of the opinion that a dam and power house of
Bulletni of the University of Texas
equal capacity will cost no more at the Mt. Bonnell site than
the repair of the old dam and power house. It will be far safer
and will have less water leakage and therefore a greater avail¬
able water supply. The cost of maintenance would be much less.
We recommend, therefore that borings be made at the site
selected near Mt. Bonnell, the result of which will indicate
whether or not it is more feasible than the old site, and form a
basis for more accurate estimates of its cost.
5£ c T/o/v o/= P/?0P05££> D/7/y
/y7~ BO/y/yeiL
Fig. 17.
If llie borings develop a conditions of foundation such as we
expect, it will be entirely feasible to build a higher dam, which
would provide a greater head available for power, and the
great area of the upper layers of water will provide a large
capacity for the storage of the frequent floods, and thus greatly
increase the available water supply. This would increase the
power possibilities in greater proportion than the increase of
cost.
We have been materially assisted by Dr. F. W. Simonds,
Professor of Geology in the University of Texas
Arthur P. Davis,
Louis C. Hill,
T. U. Taylor,
Board of Consulting Engineers.
The Austin Dam
DUMONT CONTRACT OR FRANCHISE.
On April 5, 1910, the city of Austin, by election, authorized
the City Council to make a contract with the Dumont-IIolmes
Steel Concrete Company to erect and maintain a dam 65 feet
high above low water (low water not defined) at or near the loca¬
tion of the dam formerlly erected, to overflow lands bv back
water, to construct a reservoir, filter beds and to operate and
maintain the plant. The following is a summary of the terms
of the contract:
First, the company (Dumont-IIolmes Steel Concrete Com¬
pany) was to have the right to erect, maintain and operate a
hydro-electric plant and to overflow certain lands.
Second, the company was to have the use of the old dam,
power house, salvage of same, lines and poles from dam to the
city for 20 years, after the completion of dam (the said 20 years
being the life of the contract).
Third, the company may assign the contract,
Fourth, the company guarantees the city against damages
caused by breaking of dam, in additoin to the repair agreement,
but only to the amount of all installment payments not due at
time of break.
Fifth, the company is to furnish a dam 65 feet high above
low water, and the power station with turbines capable of sen-
erating 4000 h. p., electric generators of 3750 li. p. capacity; a
reservoir of 6,000,000 gallons capacity; a filter of capacity
1,000,000 gallons per day: a pumping plant of two pumps, each
of capacity 6,000,000 gallons per day. against a head of 315 feet
above low water (or 250 fed above crest of new dam).
Sixth, the company is to bepin work within 90 days from final
passage'of the ordinance and to complete dam and machinery
ready for operation within two \e<ns.
Seventh, the company deposited $10,000 to credit of Mayer,
to be forfeited to city it' it fails to carry out its agreement,
which, among other Ihinus, provided for the expenditure of
$20,000.00 within six months.
Eighth it (kim or ^ l^iks, seepage or other
wastes of water occur affecting natural flow for power purposes.
Payment shall cea^e till repairs are made.
84
Bulletin of the University of Texas
Ninth, the company agreed to furnish the full amount of
3,000 II.P., so long as the lake level is not more than 5 feet be¬
low the crest, provided the inflow at the head of the lake ex¬
ceeds 220 second-feet, and a minimum of 1,000 II.P.
Tenth, at no time shall the company draw the lake level lower
than 25 feet below crest of dam. When the flow will not furnish
1.000 II.P., the company was to furnish steam power to make
up the deficiency, or may purchase the deficiency power from
the city's steam plant at the minimum rate.
Eleventh, the city agreed to pay 40 semi-annual payments of
.^25,000 each, the first to be paid six months after official notice
of completion od dam and starting of plant. Payments are to be
made from earnings of plant and no taxes are to be levied for
this purpose.
Twelfth, the city shall own and control the lake and shall have
the exclusive use of all power from it, except 25 II.P. reserved
for lighting and power at the dam.
Thirteenth, dam and plant shall be the property of the city
after the contract has expired.
Fourteenth, for inspecting the construction work the city shall
appoint an engineer agreeable to the contractor or his assigns.
In regard to this contract, the Engineering News of April 14,
1910, made editorial comments as follows:
"The contract is an agreement under which the city buys a
dam, and some appurtenances, on the installment plan, at a
price which appears to be extremely low. As to what kind of
a dam and appurtenances the city is to receive, the contract is
pleasantly indefinite. The plans accompanying the contract ap¬
pear to be both incomplete and conflicting. There are no speci¬
fications binding the contractor to furnish any special kind of
construtcion or quality of workmanship. The so-called specifi¬
cation is but a sketchy summary of the works to be built. The
city can inspect the works, to be sure, but the inspection must
be done by "an engineer agreeable to the contractor or his as¬
signs/ That clause alone should make this contract famous!"
There were several unique features in regard to the contract :
1. "Low water" was referred to at several places in the con¬
tract. and was not defined at a single place in the contract or
specifications, and the writer can state, after an experience of
Tlx. Austin Dam
85
over 20 years on the Colorado River, that "low water' is au
exceedingly elastic phrase at the locality referred to.
-■ 'he city had the right to have the work inspected by "an
engineer agreeable to Hie contractor or his assigns." The ad¬
jective nni<pie'' is tlie mildest that could be used in connec¬
tion with this clause.
3. The reservoir and filter was to deliver water "pure as the
present supply.1' No standard of purity was defined, and this
clause opened the way for dispute, misunderstanding and liti¬
gation.
4. The cement must be able to stand standard specification
from United States States, and should be aged cement if pos¬
sible. It would have been more effective to have said at once
that the ceemnt should fulfill all requirements, as prescribed by
the American Society of Civil Engineers.
By the terms of the contract or franchise it expired on Jan¬
uary 23, 1911. The City Council on that date declared it for¬
feited arid demanded the ten thousand dollars ($10,000). The
city was enjoined by the courts from collecting this forfeit, and
the suit may come up on its merit in March, 1911.
RAINFALL AT AUSTIN, TEXAS.
Year.
1856
1857
1858—
1859..
1860
1861 -
1862 -
1863
1864—
1865
1866
1867
1868
1869
1870
1871
1872
1873—-
Rainfall
•inches. !Year.
19.60
33.00
36.40
28.20
29. GO
28.70
22.20
34.70
25.20
37.80
40.50
27.30
40.10
38.50
42.50
30.10
33.30
43.40
1874-.
1875..
1876..
1877.
1878-
1879-
1880.
11881-
,1885.
1887-
1888-
1889-
1890-
1891-
1892-
1893-
1894-.
Rainfall
Rainfall
-inches.
Year.
I —inches.
46.50
1895
31.90
29.30
1896
21.90
32.60
1897
.. - 28.10
41.80
1898 _
25.90
21.60
1899 — ...
! 28.00
18.30
1900
53.99
48.10
1901,
20.40
25.30
1902.-
32.86
40.30
1903
36.23
32.40
1904
37.91
23.50
1905
35.85
51.80
1906
21.49
43.20
1907
1 30.40
36.40
1908
30.07
37.10
1909
20.57
34.70
1910
, 24.55
16.30
Mean _
j 32.27
27.50
INDEX.
Page.
Austin, bonded indebtedness of. 34
rainfall at 85
taxable wealth of 33
Blanton, A. C 69
Board of Public Works, connec¬
tion of with project 15
disbursements of 35
Bogart, John, employment of... 15
extract from report of 15-16
Borings at dam 69
Bulkhead, cost of repairing 33
leak in 29
Colorado River, actual available
power of 13
drainage area above Austin... 5
estimated available power of. 13
estimated minimum flow of... 13
flow of 65
maximum flow of 65
measurements of, at low level 65
minimum flow of 13
rainfall over watershed of. . . . 5
silting above dam 38-65
watershed above Austin 6
Consolidated Construction Co. .67-6.S
Contract with Dumont 83
Contract with Consolidated Con¬
struction Company 67
Cost of dam—
Foster's estimate 60
Evan's estimate 67
Government engineers 81
Cost of rebuilding, Foster 60
Evans 67
U. S. Government engineers.. 81
Cost of dam, etc., actual 35
Frizell's estimate of 15
Cost of Mt. Bonnell dam 81
Corrigan, Bernard, award of con¬
tract to 16
Davis, A. P 78
Discharge of Colorado River.... 65
Drainage area above Austin.... 5
Dumont contract 83
Evans' estimate 67
Evans' report 64
Fanning, J. T., cross section of
dam proposed by 26
employment of 25
extract from report of 56
recommendations of 26
Foster's soundings 60
Foster's report 59
Frizell, J. P., appointment of. . . . 9
canal recommended by 21
Page.
cited on abrasive action of
water at dam 48
cited on causes of failure 48
cross section of dam proposed
by 26
preliminary report of 14
resignation of 8
Geyelin, E. C., employment of. . 24
Geyelin, E.. C., recommendations
of 24
Glenn, Mayor, power project of. . 8
Government engineers 76
Groves, E. W 52
Hazen, Allen, recommendations
of 34
Head gate, cost of repairing
break in masonry of 3 3
leak under 29
Hill, Robt. T 53
Kirkpatrick, W. G 69
Lake McDonald 38
silting up of 3.S
Leak under headgate 29
Leak under penstocks 29
Length of dam 11
]\1 addox, Frank M 76
Map of watershed of, above
Austin 6
Mt. Bonnell dam 81
Palm, J. G., cited on undermin¬
ing of toe of dam 53
Patterson on foundation 62
Penstocks, leaks under 29
Pope. J. F., appointment of 15
Power house, change in location
of 24
cost of replacing foundation of 33
Rainfall at Austin 85
Report by Evans 64
Report. Foster's 59
Roberts, Governor, power pro¬
ject proposed during ad¬
ministration of 9
Seltzer, H. K., work of 51
Silting up of Colorado River
(Lake McDonald) 38
of reservoirs 43
Simonds, F. W 82
Soundings, Foster's 60
Soundings, index map of 38
results of 38
Specifications for dam 16
Stone & "Webster 62
Water and Light Commission,
connection of with project.. 35