The herald., 1897-04-20

Summarized, the available source of
supply consists of the rainfall upon the
watershed north of the Crystal Springs
property percolating toward the infiltra-
ton galleries and absorbed by the latter
This watershed embraces about 458
square miles. Calculations based upon
this, and the mean annual rainfall of
seventeen inches, and allowing for 25 per
cent reduction for a three years cycle
of dry seasons, with but a SO per cent
ratio of percolation, and reasonably as
Stunning 60 per cent of this amount to bs
intercepted by the infiltration galleries
there would be. at the most, about 3Ot
square miles out of the available 45i
square miles required to furnish the
needed ninety cubic feet needed for thi,
system.
DISTRIBUTION SYSTEM
No special consideration in determin.
ing and designing the distribution plan
has been given to the existing pipelines
of the present water works, but com.
plete new system has been evolved. ex,
cepting that certain features of the pres,
ent works, which. on account of the
favorable situation, of correspondents
size and good mechanical construction,
were incorporated in the new system.
These adopted features include the
Buena Vista street reservoir, the new
Bellevue avenue resrvoir, the main
conduits leading thereto, and the in
filtration plant of Crystal springs. Ger
tain needed additions and extensions
If followed on the lines laid down for
this system, will make these features
desirable adjuncts to the proposed gen.
eral system.
The topography of the land adjacent
to the sources of supply. together with
the undulating character of the ground
upon which the city of Los Angeles In
built, necessitates q somewhat complex
system of distribution.
1t was found necessary to subdivide
the city area into three levels and give
each level an independent reservoir ana
pipe service, however, arranged in such
manner that each level service does
not necessarily depend upon its own
resources. but can, in case Of accidents
to any part therein, renewals, etc, be
supplied partly or wholly by one of the
other level systems, Sc that temporary
and simultaneous breaks, even in two
out of the three main trunk pipe lines,
would not interfere with the proper
distribution of the water at any one
point within the city.
With this end in view, large circulat-
ing trunk lines occupying central posi-
tions to the entire pipe system have
been made a special feature of the lat
ter, for the purpose of supplying any
portions within the city limits with suf-
ficient water in case of any temporary
withdrawal of one or the other of the
distributing reservoirs.
All large trunk lines are to be par
alleled by means of smaller tapping
mains to supply demand for domestic
consumption, in order to enhance the
life and usefulness OF the large circu-
lating trunk lines, and to guard against
any interruption Of the flow of water
within these trunks.
Briefly stated, there is designed to be
low level pipe system, served by grav-
ity flow from two low level reservoirs,
the present Buena Vista street and pres
ent new Bellevue avenue reservoirs.
The main portion of the pipe system
served from these reservoirs lies south OF
Seventh street. on the west side OF the
Los Angeles river, and south of First
street, on the east side Of the Los An
geles river. including all the annexed
territory 70 the south and west. This