Evening star. [volume] (Washington, D.C.) 1854-1972, 1885-08-14
SUPPLY OF THE DISTRICT,
Major Lydecker's Annual Report.

Major Lydecker's Annual Report.
PROGRESS OF THE WORK ON THE EXTENSION
OF THE WASHINGTON AaUEDUCT DURING
| THE PAST YEAR
Major Lydecker. U. g. A., the engineer Conn
missioner OF the District of Columbia, has trans
United to the chief of engineers his annual re-
port on the extension of the water supply OF the
District OF Columbia. The report reviews the
work done during the year on the dam at the
Great Falls, the tunnel and the reservoir.
Al the beginning of the year the construction
Vi the masonry dam had been commenced
uhoer a contract with c. T. Mathers the con-
| struction of the tunnel under contract with
| beckwith & Quackenbush, the work on the reser.
| Voir under contract with Maoncy Gibson ana
| the construction of the As and rs inch mains
and main connections for the purpose OF intro
| duc1ng the new water supply into the present
system of mains, the latter work being carried
on by day labor
| THE WORK ON THE GREAT FALLS DAM
| consists of placing fifteen-inch coping on the
| Old dam across the Maryland channel, 1,O34
feet long, and building new dam across Conn 8
island and the Virginia channel ,943 feet
| long The construction of the most difficult
deep-water portions OF the dam, continued from
| the beginning OF the fiscal year as rapidly as
possible, and was completed with the exception
| OF the coping. The COnns island portion ana
| some of the shallow-water work have been
| completed. The time fixed by the contract for
| the completion OF the dam was June 3oth,
| 1885, but an extension of time until November
| LIST has been allowed. The work already done
| and the material used have cost SS1 1881, OF
| which soS,0lS was expended during the pres
| ent year. I here remains to be built about 400
feet Of the dam, averaging six feet in length,
| deep water section OF the Virginia channel, and
| LOO feet OF coping has to be placed. The APP
| prop ropriation for this branch Of the work was IS
| Sl4o,151. and the unexpcnded balance of
| SoG,oo1 is deemed sufficient to complete the
work.
THE WORK ON THE TUNNEL
| has been carried on with great skill, but the
difficulties encountered render its completion
within the time originally intended impossible,
so the time has been extended to June 80, $50.
The tunneing when completed will be 90 15
! feet long, with normal crOss-section of S2l2
sqnare feet and an average depth Of $50 feet .,
below the surface of the ground. During the
| year II ,9O7 feet OF tunnel has been dug making
the present length of the excavation 13,49S
| feet, 40 feet OF which has been lined with
| masonry. The five working shafts, varying
from % to 100 feet in depth, and the three per-
mnent air shafts have and
| cost of labor and material up to the present
| time has been :S41s,125, of which $3.50, 76s
was expended during this year. The original
appropriation TOR the extension of the acque-
| duet was S599,535. OF this sum S16O,S12 is
s sti available. The cost of the work will
| timated, on account of the characte-
| OF the rock encountered. A careful estimate
by Capt. Symons shows that 1895, 900 addi-
tional will be required for the completion of tne
tunnel. This necessity fol- an increase in the
appropriation is due to the facts that the shafts
| have to be sunk to greater depth than was at
first supposed to reach good rock; that q much
greater proportion OF the work has to be lined
| than vas reckoned on, and the amount OF eX"a-
walton and masonry are greatly in excess ot the
Estimates, owing to the variable and unsatis-
factory character OF the rock encountered.
Major Lydecker enclosed Capt. Svmons' esti-
mates, and urgently recommends an apprOpria-
tion OF the amount he asks for. The present
appropriation will be exhausted by February
next and any suspension of the work at that
! time would add greatly to the cast.
THE NEW RESERVOIR.
The construction of the new reservoir involves
the excavation OF $4,000 cubic yards OF earth.
| which is used in the construction OF q massive
earthen .lam at the lower end of the valley in
which the reservoir Is located. The side slopes
of the dam are to be paved with dry stcne and
the stream now flowing through the site of the
reservoir and all surface drainage is to be inter-
slower in progress than contemplated by the
contract, but has been well done, and there will
be no evil results from the delay. rs the reser-
vnir can be OF no use until the completion of the
tunnel The time for it, completion has been
eXtended to July 1st 1856.
The amount expended ON the reservoir thus
far is S2OO.59O, of which S146.275 was spent
last year. The earthern dam l. now 81 feet high.
Tie "ri:ina! appropriation for this work was
Si31 ,2T4. There remains uneXpended $50.
100, which will be insufficient to complete the
work, an additional appropriation OF S195.OoO
being required. he reasons IOT tnlS are MANY.
the material encountered in the bottom and
sides of the reservoir are in many places TN.
suitable for use and must be replaced by other
material, and excavations have TO be made at
greater depths at an additional cost. The stone
taken from The tunnel is found to be unfit TOR
use in lining the reservoir, and other stone has
to be secured. The original plan was to carry the
sewerage through The bottom Of the basin in
pipes, but 1t has since been decided to carry it
around. larger force of engineers and super-
intendents is found necessary, also. 1t was
first proposed to admit the water into the basin
at but one point, but to secure better circula-
ton of water, more costly project has been
found necessary. All these changes are cen
| sidered absolutely necessary to secure y pure
should lie made; the additional amount of
S35 900 being necessary for finishing the re.
servOir, &c.
The construction of the main connections has
been comp eted as far AS practicable before the
| rest of the work is completed.
About Sl62.4O6 has been expended in this
work, and u balance OF S2,99i remains, which
will probably suffice to com rlete it, The nav
ments for land condemned and used have thus
far amounted to : 3,o9S tor the tunnel; $2O7,-
246 for the reservoir, and Sis the dam.
IN A SUPPLEMENTAL REPORT
Major Lydecker says the amount estimated for
the cost of maintaining the aqueduct and pre-
serving the water from pollution during the
next fiscal year is $4,000, the customary
amount, and of which the District revenues paw
half. He says that he is advised that the bis
trict could not afford to contribute an amount
materially In @ycess OF this. and is not called
upon under tie law to provide for new works or
modification Vt present structures, to protect
the water supply from pollution. This work
should devolvc upon the War department, and
to that end an elaborate project has been pro-
OF 81 10000 for the condemnation Of the land
diverring tributary streams and removing all
possible sources OF pollution.
ROt.