Los Angeles herald., 1906-12-25

ing Fairmont.
1.-THE aggregate length of the aque-
duct may be summarized as follows:
Feet. Miles Pet.
Conduit unlined canal. 1172OO 22.2O 90
Conduit lined with rub
bic masonry or con-
crete .................. Ss6,7OO 164.5s 72.7
Tunnels, in rock. 96,295 1924 81
Tunnels, in earth....... $3.50 10.11 As
Siphons of steel pipe
crossing canyons -. 47,460 S.99 40
Steel fumes crossing
shadows and narrow
depressions ........... 9,51O 1.sO os
1,192,535 225.s7 1000
"The conduit has been estimated with
a cover of reinforced concrete for
distance of 100, 440 feet, or 11.6 per cent
of the entire lined section, the remain
years of operation.
Modification of Plan
"In work of this magnitude and on
such bold lines many trial routes must
of necessity be surveyed, their cost esti-
mated and their advantages compared
before the final line for construction
Is laid down.
''In an aqueduct and reservoir project
more trial lines are needed than on a
railroad project, because of the neces-
sity of following a gradient along which
water will flow with velocity rapid
enough to prevent sedimentation, and
not SO rapid as to produce scour, and
because of the Importance of distrib-
uting the fall so as to lessen the diam
eter and cost of the more expensive
portions of the work and adapt to each
type of ground the type of conduit best
suited for utilizing the natural re-
sources of the neighborhood in ma
terial for concrete and masonry.
Although it is now certain that the
best general line Of location has been
reached, many local variations are still
possible, and six or more months of
we'll be devoted to this matter of final
location.
This board, in it's studies and in
course OF conferences with the engineer
of the aqueduct, has been led to unani-
mously recommend the following i'm
portant notifications:
"First-The substitution of a direct
line, thus saving twenty miles in dis
tance over a very rough country and
shortening the length of the longest
tunnel by about one and one-fourth
miles, thus reducing the time required
for the completion of the work, be-
sides effecting very considerable saw
ing in cost.
"Second-The substitution of high
grade tunnel and conduit line for a
siphon of fifteen miles in length from
Little lake south, using somewhat over
100 feet of spare fall for that purpose,
thereby reducing cost and increasing
permanence of construction.
"Third-The raising of the elevation
of the entire line from Indian Wells to
Fairmont about sixty feet at the lower
end and 110 feet at the upper end, util-
izing a further amount of the surplus
fall and thus permitting the utilization
of the reservoir for storage as regu-
lator of the power plants to be built
on the drop in the canyon.
"Fourth-The elimination of the pro-
posed siphon across Antelope valley,
eleven miles in length, with a maxi
mum head of 400 feet and substituting
a conduit line passing around the head
of the valley. This increases the total
length of the aqueduct about twenty
one miles, but effects a saving in head
amounting to sixty feet, available for
storage and power.
"Fifth-The construction of the long
tunnel next to the power drop of the
larger dimensions and sleeper gradient
needed for developing a rate of flow
in the hours of maximum power de-
mand two and one-half times as great
as the mean rate flow, thus largely in
creasing the amount of power avail
able FOR sale ana Tor the development
of manufacturing.
"SiXth-We recommend that the con-
duit and the tunnel and pipe sections
have their waterways designed on a
somewhat more liberal basis than at
first proposed, in order to provide
against possible increase of friction
with age, or the adhesion OF organic
growths.
1--WE suggest the use OF the following
coefticients in the Kutter formula:
For masonry conduits of ce-
ment or smoothly plastered
masonry ....,....,..,........,. n plus ,O1S
For concrete lined tunnels, or
covered masonry conduits... plus .Ol4
For steel pipe with rivet heads
and seams prJecting on the
interior Observation-Disclosures. IL pluS 'Vlo
For earth canals with bottom
as left by dredging............ plus .O215
"In proportioning the aqueduct be-
tween Haiwee reservoir and the San
Fernando valley to convey a mean flow
of 410 feet per second. including evap-
Grafton loss, we recommend and have
based our estimates OF cost upon ca
paeity per cent greater, thus provid-
ing for delivery of 4S0 cubic feet per
second OF water in order that the reser-
Voir might be replenished within twen-
ty days after having been depleted by