Evening star., 1896-11-03
General Craighill's Report on the
Washington Aqueduct.
OPERATIONS DURING LAST YEAR
Recommendations as to the Ly-
decker Tunnel and Reservoir.
MONEY NEUTRALITY-SUSPICIOUS.

~>-'~
ington aqueduct and the efforts being made
| to increase the water supply Of the District.
During the past year" he says. in
Guiding the numerous occasions when the
water level was lowered by the supply be-
ing shut off for the purpose of making re-
pairs or of removing deposits from the con-
duit the extreme fuctuation of water level
In the distributing reServafr had a range
of but IS feet, as against Al feet for the
preceding year. This marked Improvement
is due to two causes: First. the effects of
the removal of deposits from the conduit;
second. from putting the Dalecarla reser-
voir into service, thereby doubling the re-
serve supply and avoiding the throttling
effects of a section of the by-conduit but
feet in diameter. 81
Removing Deposits From the Conduit.
Operations for the removal of deposits
from the conduit and Dy-conduits in ac-
cordance with the provisions of the act
approved March =. 1895. We're carried on
vigorously whenever it was practicable to
empty the conduit without interfering with
the water supply of the District. The plan
adopted was to open up sue CceSSive man
holes along the conduit. erect derricks
operated by horse power over them and
lower wheelbarrows. each provided with a
tub rugged for hoisting. into the conduit
The tubs We're filled by means of Shovels
wheeled to the nearest manholes hoisted
emptied and again lowered into the con-
duit When the bottom too rough to
permit wheeling spon it, wheeling plank
were used. and when the water i'm the
conduit was too deep to permit the use, of
Wheclbarrows, boats were used instead. BY
these methods G3.o51.22 Iineal feet of con-
duit and by-condut Were cleaned, and
S,946 cubic yards of deposits removed
The maximum obstruction by deposits
from ! Of he
tire area of the cross section of the con-
duit. After the deposits had been removed
the conduit and by-conduits We're scraped
and swept and carefully inspected for
cracks.
All cracks We're cleaned out and stop
ped with cement mortar. In all l1S6 lneal
feet OF cracks, varying in width from !.
to 112 inches. were stopped. These cracks
were almost without exception longitudinal
ones. and occurred where the conduit rest
ed on embankments. In order to remove
the deposits from the by-conduit around
the Dalecarlia reservoir, the serious break
of July -. 1S35 was repaired by the aid of
corerdam built in water Is feet deep. To
give additional protection at this point a
concrete wall - feet long and CO feet
wide, and containing 10 cubic yards of con-
crete, was built inside of the coffer,lam
and loo cubic yards of riprap revetment
placed in the vicinity.
Consumption and Waste of Water,
Measurements of the daily and hourly
consumption and waste of water were made
on June - ard 30. lSM. and a mean estimate
OF the two results gave the daily consump-
tion as 44.1l35I4 gallons. Based upon an
estimate of 2DUU consumers of Potomac
water, as given by the assistant in charge
OF the water department of the District
inns corresponds TO a per capita daily con-
sumption and waste of 1T3 gallons Base;
upon an estimated total population of 2S5,-
"n IN the District of Columbia. irrespective
of their source of water supply it CORE
spends TO daily per capita of 155 gallons
The great extent to which this water is
wasted Is shown by the fact that during
the hours of l to > am. when the con-
sumption is least tWo-rhiriS as much wa
ter is used during the corresponding
period between and IL am. when it IS
greatest.
The trunk mains leading from the dis
trlbuting reservoir into the city are over
taxed, and while the removal of deposi.s
from the conduit and the raising of the
dam will increase the capacity CT the sys-
TEN supplying that reservoir. but little
practical benefit will be experienced by
consumers in the city until some method
is provided for getting additional sup
ply of water from this reservoir into the
city.
increasing the Water Suppl. of
Washington.
IAN operations on this project are sus-
pehded. A watchman has been employed
uutlilS tie year AT tne new reservoir.
whose duties include guarding the stones at
the mouths of all the shafts, except the
one at Foundry branch which is under the
care of the watcnman at the distributing
reservoir.
Raising the Height OF the Dam at
Great Falls.
by act approved March . 1885, s1o5 600
of The balance remaining from the appro-
priatiOns for increasing the wafer sup
ply Of Washington. ID. c. were made
availa BILE for raising the height of the dam
at Great Falls and other works rendered
necessary by the raising of the dam. and
for damages on account of flooding of
lands and other damages. 80.
The dam extends from the Virginia to
the Maryland shore crossing Conn's Is
land. Its total length is 2.S77 feet and its
top width feet inches in the MARYLAND
channel and feet 3 inches across Conn's
Island and in the Virginia channel. The
dam is to be raised 2.5 feet. that at Its
low water stage the river vii! just. ill the
mouth OF the conduit Until December
1922 sandstone was obtained from the
United States quarry at Seneca and was
boated down the Chesapeake and Ohio
canal 10 Great Falls. On January u. ls,,;
authority was granted by the chief oil en-
giEeers TO obtain stone by contract, and Oh
March IS. lS!h. contract with Mr.. Asa b.
the chief of engineers for furnishing aboIi,
LOO c3bic yards of granite dimension
stones at SIS per cubic yard. and about 1n
cubic yards of granite coping stones al
S21 per cubic yard. Time of commence
ment Of contract, April 10, 1893: Time of
completion September -, 1896. Up 10 the
close of the fiscal year the contractor haa
furnished S23.9S cubic yards OF dimension
stones and 5.2i cubic yards CT coping,
stones
THE work of laying stone was COM
menced n October. 1895. and suspended
for the winter in November, 1888. Opera
tions were resumed on April ~. 1876, all.
continued to the close OF the !scal year
BY the use of horizontal nova Bile wooden
shutters and sand bags, and by cauiki:ig the
smaller leaks. cheap and efficient Golfer
dam has been devised, by means OF which
stone has been laid against head Cf fcur
feet the crest of the dam Ripran FOR
reSetting the upstream side of the dam is
obtained from the government quarry at
Seneca. and is boated down the canal. .
"At the close of the fiscal year the dam
had been raised to the full height for IA dis
tance Of 1,:'94.S feet, and riprap revetment
had been placed for a total distau.e ,,f
1,S25.S feet
"A suspension galloway was purchased nv
contract in November, 1895. for $40 o4., and
has been in constant use since April lS.,6
If ordinary conditions of the river prevail!
until winter, the dam will be completed
during the present season. Ii is believed
thof b:,1a Of he -,