Evening star. [volume] (Washington, D.C.) 1854-1972, 1895-11-26
THE DALECARLIA RESERVOIR
Final Report Of Col. Elliot, in Charge Of
the Improvement.
Extent of Work Done to Prevent the
Contamination of the
Stored Water.

The chief of engineers has received the
nnal report of Col. Geo. II. Elliot Cretired) on
the improvement of the Dalecarlia (rece.v-
lng) reservoir. This reservoir, lying partly
In Montgomery county, Md, and partly in
the District of Columbia. was constructed
for the storage of Potomac water from
Great Falls. Prior to the present improve
ment, it was contaminated by the water
flowing into it from it's watershed OF about
1000 acres. The object of the improvement
was the diversion from the reservoir of this
latter water, which formerly entered the
reservoir by three streams, viz, East creek,
Mill creek and Little Falls branch. and also
flowed directly into the reservoir from the
hil,sdes between these streams.
Project for the Improvement.
The project for the improvement provided
for the erection of dams across the valleys
of all of the streams just above their
mouths and taking the water of East creek
(the stream farthest to the last that polluted
the reservoir) from behind its dam, and con-
Quoting it by an open channel around the
margin of the reservoir, together with the
water flowing directly into the reservoir
from the hilisides between East creek and
Mill creek, into Mill creek above Its dam
The combined waters of both streams and
the water falling directly into the reservoir
from the hilsides between Mill creek and
Little Falls branch are now carried by
proportionately larger channel, still follow
ing the margin of the reservoir and short
tunnel into the Little Falls branch. Finally
the water of the entire watershed thus
collected is turned into a shaft eXcavated
In the valley of the latter stream above its
dam, and from the bottom of this shaft
tunnel about a thousand feet long, has been
excayated unde- Dalecarlia Hill and under
Aqueduct tunnel No. 4. This tunnel is in
tended to carry the water to a natural wa
ter course below the reservoir, In which IT
flows off into the Potomac. The estimated
cost of the work was Sl5O.OOo, and that
amount was appropria ted by Congress in
three annual installments on and since
March 3, 1898.
Work Recently Done.
A portion of the work accomplished since
Col Elliot's previous report was the OK
cavation and grading at the head of the
reservoir; the earthwork at the Mill creek
and Little Falls branch dams; the masonry
work at the outlet of the channel leading
from East creek into Mill creek; the raising
of the banks of the channels to their full
height of one foot above the flow line of
greatest floods; the construction of two
wagon bridges near the west portal of the
tunnel under Dalecarlia Hill and the con-
struction of roads to these bridges. In adj
dition three lattice bridges have been con-
structed across the open channels, two over
East creek and the otter on the route from
the north cOnnectlOn the tunnel SnaIt
A wagon road has been constructed from q
point on Brookes' Hill to Mill creek dam,
and this dam can now be reached by wagon
or carriage from the Conduit road. stone
suitably marked has been planted at the
point where the boundary between Maryland
and the District of Columbia crosses outer
bank of the channel leading from East
creek into Mill creek. The crossing of this
line over the Conduit road was similarly
marked.
Cottage for n LabOrer.
A small frame cottage has been construct
ed on the line of the works of improvement
for the occupation of q laborer whose duty
1t shall be to keep the works in good order
and repair, and especially to keep the chan
nels and the grating around the shaft free
of drift wood, ice and other distractions
tending to prevent free flow of water INTO
and through the rain drainage tunnel in case
OF storms or heavy showers. The cottage is
located on Brookes' Hill near the eastern
end Of the DAM across the valley of Little