The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1878-05-03

!, MAY 8, 1878.
left for this purpose, and the way reserved
for thirty-six-inch pump-main from the
pumps to the new reservoir, to be laid when
the additions in the future OF other wheels
and pumps are made.
This plan will utilize as water.power
the whole quantity of water In the river at
the point indicated when at it's minimum
works or mill-poWers now in operation
below. 1t locates the. works at q point far
enough from the city to keep the water free
from contaminations by future sewerage or
manufactures which may be placed in the
vicinity Of the present pump.works. The
location is in distance from the new reser-
voir only 3,610 feet as compared with 9,450
feet, Che distance OF the present works from
this reservoir, and In elevation it is 46.10
feet above the river at the present pump
works, making the elevation necessary to
be overcome in raising water to the new
reservoir 1913 feet, instead OF 207.4S feet,
as it is from the old works.
A modification Of this plan, which avoids
constructing new dam, would be to use
as water-poWer great quantity of water
OF the James River and Kanawha canal,
taking it from the upper level at the Three
Mile locks and discharging it either into the
lower level or the river again. The objec-
ton to the use Of the canal for water works
purposes is the interference with its navi-
CATION, and long line Of works requiring
expensive changes and repairs to guarantee
q constant and uninterrupted flow OF water.
An approximate estimate shows that this
plan will cost at least $4,000 less than any
OF the other plans mentioned, so that it is
unnecessary to make close and detailed
estimate OF the total cost Of it until certain
rights are agreed upon between the city and
canal company and the necessary land-dam-
ages are ascertained.
OTHER PLANS.
Water Poner at BoSher'S Ddn.-The To-
cation of pump-works at this point would
still utilize nearly the whole flow of the
river by using the wafer power available In
making use OF the dam already constructed
by the canal company, and the pumps
would be only 1898 feet below the new
reservoir; but the distance is six and half
miles bevond the Three Mile locks, and by
the most practicable route for pump-maln
is about seven uiles from the new reservoir.
2'he distance in the length OF puqnp-main
is too great to bring the cost Of this plan
within any close comparison with the plan
proposed; but when the consumption oil
water exceeds the capacity of works located
at the Three>MSle locks TO supply it new
| location wihithen be needed, and BosheT )
dam will in sall probability be selected for
the purpose
STEAM POWER
The usegf steam machinery for pumping
would avoid the construction OF dam aHC
other arrangements needed an water-poWel
machinery, and in. location it could ot
placed beyond the range OF floods; but tht
annual scost in the running expenses o.
steam machinery, together.W with the lnteres'
on its first cost, would represent total an
nual expenditure so much greater than the
amount represented in either of the water
poweriplans that, upon the ground of econ
omy, Il is not to be compared with them.
Under date of April Is, 1878, the Super
inten6ent of the Water-W orks reports oth
cialIy' the daily cost of operating the eigh
wates-power pumps at S32.3f, and the daily
cost CT operating the steam-pump at S21-0l
When it is understood that the capacity o
the s3eamp-pump is only one eighth Of al
the other pumps together, it is clearly seer
that sthere is no economy in using steam
machinery in our Water-Works.
GRAyrTATIoN.
The question is often asked, Why nu
bring water to the city through pipe ear
rieti high enough up James river rs TO 81
lowthe water to flow by gravitation, there
by avoiding the use of pumps and re
seryoirs? BY reference to the map of tht
James River and Kanawha canal it will be
seen that at sixty-eight miles above the
Three-Mile locks an elevation is reached or
leTel with the water-service OF the new
reservoir; and to get the additional eleva
tion required for the water to flow through
a proper conduit it will be necessary to 90
atleast seventeen miles higher up the river
making a total distance by the canal O.
about eighty-flye miles from the reservoir
II we look TO the South Anna and Apo
mattoX rivers, the only other sources o
supply where water can be found i'll sufl
cient quantity at the required elevation fol
gravitation flow, an approximate mea
surement can be readily made from reliable
mans to show that distance of not les
than thirty miles from the city is necessary
for the purpose. The great distance neces
saryto 60 to bring water by any gravitatior
method shows that it is not economy tt
adopt such plan.
ELLETT'S PLAN.
(See report to Water Committee, 1858, by
Charles Ellett.)
This plan proposes division OF the sup
ply into two services, drawing the water
for all the lower portion OF the city up tt
an elevation of seventy feet above NEAR
tide directly from the James River and IA
|.nawha canal, and using the, pumps Tor al
the higher parts OF the city, In looking tt
the future increase of pumping capacity
this plan proposes to use water from tut
james River and Kanawha canal opposite
the present pump-works as water-poWer
A very small part OF the present con
sumption, not over 100000 gallons, woult
relieve the pumping capacity, il this part o
the plan of drawing water from the canal
basin had been carried out; and if the new
pumps erected in 1874 had been run b!
| water-power from the canal, as proposed il
this plan, in low stages OF the river eithe
the water-power of the city mills would b.
seriously interiered with or the new pump
would be idle II this entire plan had beer
carried out there would still be necesslt.
for increasing the pumping capacity, ant
locating the pumps at some other than tn
present works.
During the favorable season Of last sum
mer, when the flow OF TIE river was les
than ever known before by any recort
which have been able to find, a careful
gauging was made of the river and the ca
nal to determine the minimum quantity O.
water flowing at the time in each. Th.
minimum quantity Of water flowing in tn,
/ river was found to be 1882 cubic feet PEI
second, and the minimum quantity drawn
from the river into the lower canal level q
the Three-Mile locks was found to be 35t
cubic feet per second. Every cubic foot o
water which could be made available at tn