Evening star. [volume] (Washington, D.C.) 1854-1972, 1893-01-07

his reservoir must be prevented from filling
up with water to any marked degree by an out
let having sufficient capacity to provide a
free discharge for the stream during the
heaviest and most prolonged rainfall
that may be expected to occur throughout the
basin. With the project carried to completion
the gap between Washington and Georgetown
will cease to exist, and den ely populated area
will be subject to flooding and possible disaster
il the dam be overtopped. The outlet once
built, it's capacity will become practically fixed
quantity. while the capacity Of the basin to pro-
duce higher and higher floods at the head Of
the outlet will constantly increase its surface
passes from a rural toward an urban character.
A further danger, which must not be over
looked lies in the fact that great freshet in
Rock creek may be expected to bring down
large trees, portions OF iron and wooden
bridges and other debris in large quantities
Unless the covered channel be made of
ample dimensions its mouth will be subject
to stoppage by drift of the kind described
Whether . flood in the city would follow
or not would depend on the period required to
fill the reservoir formed by the embankment
over the covered channel and the possibility.
which is by no meansapparent. of clearing away
the drift within a reasonable time. The con-
tents OF the reservoir are estimated at III 000,-
900 cubic feet. With water entering at the
rate Of 20, 900 cubic feet per second and none
leaving it the reservoir will be filed in about
two hours and one-half.
THE COVERED WATERWAY.
The profile of Rock creek will conveniently
allow a slope Of in 1000. Assuming this fall
there has been designed the waterway shown on
the accompanying section. The span is fifty
roa ~ a. a.n.; 20 49, .ee' anu ,rie ,o',i
tom is provided with central depression to
carry the dry-weather flow, and is otherwise SO
arranged as to facilitate cleaning should that
prove to be necessary The lining Of the bottom
r;,r;fa -. -; ms u "a, 81 80, ". VI
The side walls Sd tha ,om,oh; u' o",o se';
6rst.class rnbh,a masonrn a,,1 r. or III, ,Sa
best brickwork carefniiy bonded As thus ,ns
5Ss;cred This w.t,,r,rav .,';,, IT,. e,I, mus
he asnected 70 ca,rv ~ Ju,r la,i . may
~ 00o cnhic feet r.sr sacond I an,sroo, ,na
Increased ,nant;t;.s M -. ,o..I - hs
"a 600 cub,c feet nar secand can no d;schapoaS
without nntt;nC he mssnnrv ., ,ho orn,n,o 20
tho srch ppn5ar $500 'S,a.y ~ no .io"n VI
70 head nY ahon, A.. a9S .nsn 'n"' uue
II will he noted tb,.t the NAV Snhro;ttad h.r.-
nth nroy;das for ;nf.raont; 20" su n.n- n LII
the sewage ~ Washinotan ga Cno ~ Ae.p
from entering the arcbeS watar-o t6St.S.,,.
this precaution n larpe mass ~ saw.oa vii, h,
thrown in front of the heart of Washington.
result which any rational scheme of sewage
disposai must ann to prevent. Furthermore,
a. neay an ,ne sewage must ultimately be
punpeu, l's ,oiushe must not De increased by
.ue or ,wea.ner nov OF tns creek, which Is con-
sr E,o.;d. me r.oen oseeA tntercepting system
s oih r.oIiu1 a'eHup sUuin"ara can De punt
.Ei = coAparat.ely smaii sam taoout S2o0.o00
~nieu ua' pes" a"cl1oeo IN my annual estimates
I r each OF .ne nscal years is9S and 1884; From
TIoliaa aselue nor!1Waro nearly 70 Woodley
h ns io ;s 'rS eas. sue inteHcepIing sewer mas
peeh iaiu. me west side sewer Is yet to
t ye ron n.t s;a M essmatea cost up to
tended ia s5o 5O0, II mnst he cors,anti. 49,.
in mind that sewerage Intervention for the nor
ton of the Rock creek valley under considers
ton Is matter entirely distinct from remov-
ing the barrier to the closer union of Washing
ION anu ueorge.owh, oy forcing the creek to
r,a,.d co., ahnvt saNo nnn :, ~" iolmer, esti-