Evening star. [volume] (Washington, D.C.) 1854-1972, 1896-05-12
WASHINGTON AQUEDUCT
Capt. Gaillard's Report Of Operations Dur
ing the Month of April.
Work of Raising the Dam mt Great
Falls Not Yet misunderstanding
the Deposits from the Conduit.

Capt D. D. Gailard, corps of engineers,
has made a report of operations the
Washington aqueduct and accessories dur
ing the month of April, from which it ap-
pears that during that period the water
at the effiuent gate house at the iistrib-
utins reservoir was clear eighteen days,
slightly turbid one day. turbid three days
and very turbid eight days out of thirty
days He says that during the month the
height Of water at Great Falls varied be-
tween 140 and 1909. and its condition has
been more satisfactory than for months
past. The work of crushing and placing
hint stone on the Conduit road was car
ried on during the entire month and the
work will be continued during the present
month Repairs will also be made to the
dirt road between Great Falls and the
club house.
Raising the Dam.
In regard to the project for increasing
the water supply by raising the height of
the dam at Great Fails, Capt. Gaillard
says that the stage of the river was SO
high that it was impossible to begin lay
ing stone until April 20, and even then
1t was done Under great difficulties, the
depth of water pouring over the crest of
the dam was over two feet. By the
of sand bags and movable wooden shutters,
a cheap and efficient cofferdam has been
devised, by the aid of which stone has
been laid against head OF nearly four
feet on the crest No stone has yet been
furnished by the contractor, but he reports
that he has a large supply ready for ship
meht. which will reach Great Falls
some days before the supply on hand
VIII be exhausted. If such is the
case, Capt. Gallard says, no inconve-
nlence or delay whatever will result to the
United States: Riprap for the dam is OBJ
famed from the dump heap of the govern
ment quarry at Seneca, and is boated down
the Chesapeake ard Ohio canal 10 Great
Fails AT the close of the month the con-
dltion of the dam was as follows:
East of Island Rock" in the Virginia
channel, the dam had been raised to a ref
erence of lob fee: for a continuous dis
lance of 1888 feet, and the coping had
been removed for an additional distance
OF 633 feet. Riprap reNetment had been
laid for distance Of St3 feet, and clamps
anu anchor bolts put in for a distance of
6565 feet.
West of Island Rock" the dam had
been raised to reference of 1903 feet for
a distance of IA feet. and to reference
l452J feet for an additional distance of
- feet. The coping had been removed 70.
a distance of *: feet. and riprap revet-
ment laid for distance Of 1876 feet
Removing Deposits in the Conduit.
Good progress is reported in the project
Tor removing accumulation of deposits in
the conduit. On the Great Falls division
the conduit has been cleared from the
Great Falls gate house to the west end Of
the tunnel at bridge No. 3. The work dur
ing the month completed the cleaning of
the Dalecarlia division, from the Dale
carlia reservoir p the east end of the
tunnel at bridge No. 3. The total dis
tance cleaned on both divisions was $500
1eet. The amount of sediment removed
was 1,i2j cubic yards. The total length
of the conduit yet TO be cleaned is $50 feet
The length of the by-conduit at the Dale
carila reservoir yet to be cleaned is 23D2
1ee,, and OF that of the distributing res
ervoIT is 2.y14 feet
The work of repairing the break of July
"a, lSo, in the by-conduit at the Dalecarlia
reservoir was completed during the month
A longitudinal crack has been discovered
at the top of the arch in the short sec
ton of conduit between the :wo tun-
nels near bridge No. 3. Ii is 1I9 feet
long by half an inch wide. 1t is expected
that the deposits in the conduit and by
conduits viii be entirely removed during
the present month. The work of ffling
with cement mortar all era ks discovered
In the conduit will be carried on whichever
1t is practicable to shut off the water from
the conduit.