National Republican. (Washington City (D.C.)) 1872-1888, 1879-02-26
THE WATER SUPPLY.
Plans and Estimates for Extending
the Aqueduct
Submitted by the Commissioners to the Sem
ate. District Committee--A Conduit and
Reservoir North of the City-Lieu-
tenant HoSic's Report Upon
tho Project - Cost of
Construction, &c.
increasing water Facilities.


In answer to the request of the Senate Com
mttco the Commissioners yesterday trans
mitted to that body estimates for the compile
ton of the aqueduct from the present distrib-
uting reservoir TO point in the vicinity of the
city Of Washington, for the construction Of
distributing reservoir of n capacity of 235,0O0,-
900 gallons, the connection of the reservoir
with the present distributing mains, and for
he completion of the dam Mt the Great Falls
of the Potomac. These plans contemplate the
com pletion of the water works and the devc'
opmont of the full capacity of supply. Tac'
ings showing the lines selected aud profile of
the country were also forwarded. Tho time
allowed has been too short to admit of prcpar-
ing plans for many of the minor details of the
conduit but tho general plan has been sulli-
GENTLY studied to determine within a narrow
limit the ultimate cost of the entire work
The principal work to be done consists in the
construction of conduit nine feet In diane.
ter, mostly in tunnel for distance Of 2l,10O
feet. This tunnel will he driven for about
two-ffths of its length through hard blue
gness, and for the remaining three-tifths
through clay and sand. Its level will be that
of the bottom Of the present reservoir. The
conduit will therefore be run under pressure
but very much less than that employed in
other works which have been constructed in
this country.
1t is assumed that at various times the water
must be turned of from the conduit for some
days for purposes of repair, aud an estimate is
added for the cost of Il reservoir sufficient to
supply the city during such an interval. This
involves in addition to the expense of con-
structon, a large item for the condemnation
of land in addition to the right OF way and
condemnation along the line OF the conduit.
/ A. al
thirty feet. The cost may be reduced ut the
expense of the storage capacity, by reduc-
ton of the depth. The point selected for
reinforcing the present distributing mains is
| that from which they radate to South Wash
ington and Capitol Hill. The mains in the
| extreme northwestern section of the city may
be reinforced mt the highest points by short
connections with the conduit, as may become
necessary. The principal connection and the
only one that WILDE necessary for many years,
will be by Il l-toOt main, 5000 iccS III length,
| from the reservoir and down New Jersey ave-
| nue.. The estimate of 100000 for the CON-
| pction of the dam at the Great Falls has been
| taken from the previous estimates by others,
| that part of the work not being under the
| charge of the Commissioners and the amount
may be larger than will be found necessary at
| the present time
The communication of the District Commits
missioners to the committee was based on the
following report made by Lieutenant HoXic,
who has given the subject long and careful
study, to Engineer Commissioner Major w. D..
! Twiuing:
LIEUTENANT HOMES REPORT.
have the honor 70 transmit herewith plans and
| estimates for an additional supply OF water for
! Washington and Georgetown. 1t Is proposed to
bring IN this supply by meaus OF 9.ioot conduit
from the distributing reservoir To an available site
for another reservoir east Of seventh street west,
thence for the present, by ifoot caSt.iron main
along New Jersey avenue to the principal mains,
which now rallate from the vicinity OF l. and q
streets to all points of Washington and Georgetown
The Pinch main along boundary street is also Ia
be connected with the new main.
The accompanying plans aud profile give the
location of the conduit reservoir and I-iOot
naiu The line of the conduit Is carried close &c
the northern boundary the city and viii be pro
vidrd with outlets for tapping at Intervals WIN
other mains, as the future supply may require. III
order to retain the service OF the present dstrDnt
ing reservoir the conduit Is made to tap il at the
bottom. The shortest ana most practical line I
taken and to avoid land condemnation this fol
lows as much as possible existing streets anc
| county roads. Rock Creek may be crossed ethel
by gang of long cast-iron mains laid as siphon
through the bed of the creek or by a TUNE
, through the compact rock which uuderlIcs tht
stream. If boring IN this rock is satisfactory, th'
latter method is, believe, the best aud cheapest
The former has the advantage of requiring for tn
. present only as many m0ilis as are necessary 10
. bringing the requisite supply OF water, WIN pro
: vision Tor adding others when needed. II Is, now
Z ever, perishabc construction, whl!c, the ioTme
method Is for all practical purposes eternal Tn
T. line is so placed that the conduit rests Throughout
on the natural ground, where not in tunnel, and
}. protected where covered by embankment, by sid
n walls computed TO resist independently the cntr
water pressure II is maintained that this conduit
will bring TO the city at the site OF the new resel
vor, the following quantities OF water, in roun
y At iii ieet above tide 100000 gallons; at II
feet above tide, GgOO0OJD gallons; at ll25O fec
above tide 100000 gallons, az lil.75 feet oboy
tide, 9g0OOO0O gallons; NJ lil9l feet above tid'
- OJDO00 gallons; at 1851 feet above l3LVO
900 gallons at l3sSS feet above tide j90OJOO0 ga
{ Ions; at 1870 feet above tide l7S0lO0OO gallon!
, The latter quantity Is little beyond the safe linn
for constant service giving velocity of about Ia
Q feet pcr second but the conduit VIII DO capable L
II delivering for limited time at l22OO rect aboY
tide, 100000 gallons in tweny-iour hours, On
velocity in this being Go feet per second. IN
;, amount which may be taken from the distributin
reservoir at Ij feet will depend upon the height
! the dam to be constructed across the Potomac 4
! the Great Falls and the safe limit of head undo
Il which the upper conduit may be run.
+ The capacity of the new conduit VIII OF course b
much greater than that of the present conduit irol
:, the Great FAILS on account of greater head bein
available. do not think II advisable TO distur
the existing system of mains leaking from the di'
tributing reservoir aud now supplying NashingtO
5 aud Georgetown, at least until the new cOndu
shall have been for some time in successful opera
advisable to retain them as reserve source OF SUI
ply In case of accident 10 the lower conduit. Owe
j. The whole line of the conduit is proposed TO COZ
!, denim roadway sixty feet wide wherever the lin
leaves existing roads and streets and this object M
II been kept in view In selecting the route.
The site selected for a new reservoir is centra
and gives the greatest storage capacity nearest tn
: city and at the least expense The ground iOr IN
. | Site should be condemned and purchased at ono
= together with siXty-lccJ roadway running sout
r TO Boundary street This lUwline Of the resetvoi
with depth of water thirty feet will give storag
capacity approNimating 25.OODOJJ gallons
I. The following are the estimates for the col
}. struCtion Of the conduit reservoir and A'fot
d maiu
I DAMAGES
\, Condemnation on land.)
10 acres for reservoir at $500 per $50
2L7 acres around reservoir, at $500 per acre. 1870
90 acres between gatehouse and Four
J. tcenth street, NJ 500 per acre.".,.,..... 81