The herald., 1894-09-19
THE RIVER COMMISSIONERS,
Important Report to the Board
of Supervisors.
Work Mapped Out That Will Cost
$2,761,44O.
Engineers Gall Attention to tho Damage
by the Los Angeles and San Ga
brisl Rivers and Make Plans
to Prevent 1t.


Yesterday Messrs. Wm- T. Lambie,
Alfred R. Street and Charles T. Healey,
the commission of engineers to examine
she Los Angeles and San Gabriel rivers
and make plans and estimates for con-
fining them within prescribed bounds,
made long and comprehensive report
to the board of supervisors.
The report minutely describes the two
rivers and the conclusions arrived at by
the commission in accom- panying tables
and maps. In the course OF the report
the commissioners say:
Our examination OF the old and new San
Gabriel rivers shows plainly the process OF
building up by VIII ch these valleys have bseu
filled in as the dumping grounds of our rivers,
which, after having run in one channel with
out bang connneu, naturally fill up its bed to
a level above the surrounding country aud
then breaking out on the lower side form
new bed on lower ground, and commence
again the Old process of filling up. This has
resulted, in late years, ia a new channel for
New river, and also a new channel for Old
rivera few miles from the mouth of each,
where the grade has been reduced to a mini
mum, and the quantity of material dumped to
This process has been allowed to proceed
with so little hindrance that after reaching the
limit of country through which the natural
grade would compel a scour we 1nd the chan
mel 30 small as to afford but little guide to the
immense foods that follow on their line, and
consequently the country on both sides in
many cases is flooded and rendered unsafe for
hab1tauOn or crops.
The Los Angeles river IS a striking example
OF this. Previous 10 the flood of December 25,
1889, when the river broke through at the
south city boundary and flowed through the
aguna ranch, a lerge country was inundated
nearly every winter, by reaeOn of no defined
channel, and the country was of little good to
those who owned III but now that the water
has been diverted by another route TO the Old
San Gabriel, the country once covered by the
Los Angeles river has been converted Tor many
miles into productive fields Of corn and alfalfa,
and traces OF the river channel are dificult to
find after passing south from the crossing of The
Southern Pacific railroad, on the Anaheim
branch; SO that we consider it good policy and
great economy to recommend the merging Of
the Old San Gabriel and the Los angeles rivers
into one channel at point in the Old San Ga
briel rs miles south fiom the south boundary
Extensive and detailed Typographical sur
veys were made by your county surveyor, Mr.
A. r. Street, of the several cnaunels of old and
new river from tide water to the mountains a
distance of about 80 miles, and of the Los All
geles river from its junction with the Old San
Gabriel river to the southern city limits, about
IL miles
The san Gabriel river has its rise in the Sierra
Msdre range. the water shed tributary thereto
being about 100 square miles. This estimate
refers to the mountain port on onlv above the
mouth of san Gabriel cafioD, near Azusa,
known as hODer1 point.
After passing through the valley, distance
of about II miles, to point near the Old Mis-
sion san Gabriel, the river is augmented by the
influx of the Arroyos Hohdo and Pu N te which
have water shed of about 152 square miles
each.
The Los Angeles river rises in the San Fer
nando valley and surrounding mountains,
the PacOima, Tejunga and Arroyo Beco being
Its principal tributaries, the entire watershed
above the city OF Los Angeles being about $40
square miles
-, Previous 70 1889 it formed its junction with
the Old san Gabriel river at p lint abou. IL
miles below the southern limit of the city of
Los Angeles.
In December of that year 1t flowed over Its
banks n =ar the city limi and ran to the east
ward through the LaguHa rancho, desl slroying a
very large amount of property, spreading out
with no well-dehned chsnnel, liable at next
food to cut its way to the Old San Gabriel river
wherever the obstacles opposing it might be
weakest
Except in the rainy season and few months
following, there is no continuous stream in
any OF these channels, the water sinking and
rising at intervals a consequence, doubtless,
of the varying compactness OF the strata un-
derlying the sand and gravel of the river bed.
In times of flood the waters fill Its channels
and overflow the country to width OF several
miles, frequently destroying large areas of the
most valuable land In tbs valley, the very lands
most endangered being OF fine alluvial forma-
ton, most productive. and most liable from To-
cation and com position to damage from flood
during years OF excessive rainfall.
No works of permanent character have an
yet been constructed TO prevent this damage,
magnitude and importance Of which is not gen.
orally appreciated.
1t il obvious that any works for protection in
order to possess any value must be permanent
and necessarily expensive. 1t IL useless to ex-
cavate channels or to build levees to be oblitel-
ated by tn, next flood, leaving no trace of their
existence, has been not lnfrequen ly the
case. The large area of arabic land in jeopar y,
estimated to be over 100, 600 acres justnes the
building of frst-class works for protection.
The question of providing the necessary
funds for this WORK We deem 1t not our prov
ince to discuss.
Care full measurement of high water marks
and cross sections msde at several points near
the mouth of San Gabriel o. non led to the esti-
mate that the volume of water passing through
the channel in time OF food would require q
waterway 500 feet wide and 10 feet deep upon
o grade of six feet per mile.
To prevent erosion from too rapid current,
II is recommended that the channel have
width sufficient to limit the velocity to the
rying OF matter from above without deeping The
channel below desirable level. We may state
IN this connection that 1t is our opinion that
the present official channel of the Los Angeles
river through the city should have been made
wider, as in course OF time 1t will Cut to
depth which will endanger the bridge piers and
bulkhsad foundations and make necessary ex-
pensive epairs to those structures.
Probably at no point on the river is there
greater necessity for substantial levees than at
the point referred to near El Monte
The towns of El Monte and Savanna are liza
Bile 10 be swept entirely away
large area of the finest alfalfa land sur
rounding these towns is also in danger.
Near the old San Gabriel mission st the point
of diversion of the rivers in 1868, before Ie.
ferred to. it will doubtless, III the interests of
irrigation facilities be necessary 10 divide III >
channel, providing for one half the W tter 10
flow In the old and new channels respectively.
To effect this substantial structures will have
to be erected, the details of which are herewith
given.
Referring to the large Typographical map, it
will be seen that we have endeavored to
straig hten the chsnuel lines ss much as po 81
e, to accom- piish which in many cases 1t will
be ecessary to occupy new ground altogether,
leaving the old channel entirely.
This, LEGALLY, may be deemed a hardship. but
no works OF this character ran be carried for
ward without an apparent disregard of local
property rights, al OF wh ch can, however, be
atisfaetorly adjusted by the ordinary process
lot OBJ aiming rlgnC OF way, as customary in all
ca es where the end to be Obtained results in
tns greatest good to the vrestest numDer.