Evening star., 1905-11-06
THE LOCAL AQUEOUCT
Special Chapter in Gen. Nc
Kennels Report.
MORE MONEY REQUIRED
INCREASED WATER SUPPLY BAD
LY NEEDED.
Would Avoid Danger of a Famine
Plain Language Used About
the Matter.
MORE MONEY REQUIRED

Gen. Mackenzie. chief of engineers, in
his annual report, devotes a special chap
ter to the Washington aqueduct and the
new filtration plant Estimates for next
year are submitted as follows: For build
ing combined storehouse and stable at
Great Falls, 5000; for preliminary sur
veys for additional conduit from Great
Falls, $4,000; for operation. maintenance
and repair Of the aqueduct and Its acces-
sories including the Conduit road. the
Washington city reservoir, and the Wash
ing aqueduct tunnel, S33, 600; for mainte-
nance and operation of filtration plant,
mostly for compensation OF superintendent
and employees Sl05,1
The danger of a water famine by acci-
dents to the aqueduct system and the ne
cessity for providing means for an in
creased water supply are pointed out in
plain terms by Gen. Mackenzie. Meas
urements of the quantity of water flowing
into the distribution system made In the
month of June" says the chief of engi-
neers. showed daily average Of 6S OO0. 900
gallons. This Is the largest measurement
yet made. The quantity Of water used by
the United States in the federal buildings
and reservations may now be closely esti-
mated at 1OO00.COO gallons per day. based
on actual meterings by the District au-
thorities at majority Of the points of
Ions from the total consumption and taking
the population of 1905 from the police CEN
sus. per capita consumption of 10 gal
Ions results. The measured supply to a
purely residential district Is nearly as
great from midnight to m. as from noon
to pm. During the cold weather in
February the quantity passing into the
mains varied from 20 100000 to 1O3 OO0, 900
gallons; the reservoirs were depleted until
the total reserve capacity was but one
third of the normal and less than two days
supply. notwithstanding the fact the con-
duit discharged the unprecedented quantity
of 91,OO0OO0 gallons. The filtration plant
which will be put in operation before the
next winter has maximum capacity OF
100000 gallons per diem. Any excess OF
this amount must be supplied by the intro
duction of unfiltered water into the mains.
Nearly Fifty Years Old.
'The conduit form Great Falls to
Georgetown was built nearly fifty years
ago. Attention is invited to the danger
of an interruption of the supply by an ac-
cident to the conduit. This structure has
stood for nearly half a century. ana with
out interruption in its use other than to
empty 1t periodically for cleaning. This
TACT is no guarantee that 1t will not be
interrupted in the future
IL includes SIX tunnels, aggregating g.
Io hnear feet In seamy rock and unlined
Ihey cannot be lined until a new conduit
rock are found to have been dislodged
from the roof. There is an appreciable
risk of more or larger pieces falling in
sufficient to block the tunnel for a con-
siderable time
There are twenty-six culverts nearly
all In made ground, the failure of any one
of which would break the conduit. They
are OF massive construction. but eouaIIv
strong ones have been washed out and
these may be.
Dalecarlia Reservoir.
1.-THE Dalecarla reservoir is formed bv
an earthen Dam across a valley. In this
dam is the by-conduit. If this dam should
break. the by-condult would be DESTROYED
and the supply of the District completely
cut off.
1.-The statement Is 1ustifable that. not
withstanding it's fifty years of untnterrupt
ed use, the Washington aqueduot is more
Vulnerable than the average of similar
structures and that there is risk OF an
accident to 1t which would cut off the
supply for a period long enough to cause
a water famine which would involve a
cancellation of all fire insurance and a par
ual depopulation of the city, besides other
and more calamitous consequences This
risk be underwritten by the construc-
ton OF another conduit, and in no other
way.
THE construction of a second conduit pre-
sents some important incidental advantages
1t will settle the question Of supply until
the District contains more than twice its
present population.
The Filtration Plant,
"The project for the second conduit should
Include adequate reservoirs, and may be
made TO more than double the present re-
serve supply. This will remove the single
defect in the filtration scheme 1t Is con-
csded, and has been officially stated. that
the filtration plant will probably not pro-
duce an effluent entirely satisfactory as to
color at periods of maximum turbldity in
the river. To double the reserve reservoir
capacity will permit the headgates to be
closed during periods of maximum turbidity
and insure clear effiuent at all times.
The increased sedimentation will slightly
increase the capacity OF the beds for a given
d given capacity.
with the idea of insurance paramount
the new conduit should not be built along
side the present one, but should follow a
radically different course, to reduce to a
minimum the chance of single cause dis
abling both. For this reason all possihle
alternative routes should be examined and
the preliminary surveys become more i'm
portant and more extensive and will re-
Quire more time.
IAN estimate of $4,000 for these SURVEYS
Is submitted and its favorable consideration
Is urged. The cost of these surveys and
any probable cost of second conduit will
be very cheap insurance against the IN
terruptfon of the water supply which will
remain a constant menace to the District
II ,0t Inc &c