Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1880-02-04

GENERAL REVIEW OF THE sUBJECT-THE
STREAMS AND FLOOD WATERS OF THE VAL
LEY.
The streams which enter the Sacramento valley
all torrentia in their character-that is to say,
they subject TO sudden freshets Of considerable
magnitude, but generally of short duration, caused
by the immediate and rapid drainage of large por-
ton OF the waters Of rainfall from their mountain
watersheds.
These freshets come at intervals generally OF
greater space of time than The duration Of any one
period of full flow; the occasions are exceedingly
when all of the streams are IN high flood at the
same time, even in consequence OF the same
storm and ordinarily the waters OF one freshet
should be well out OF the valley before those OF an
other came into it.
The freshets OF greatest magnitude in the Sierra
Nevada streams which enter the valley from the east
1.-THE Feather and the American) and which are the
larger tributaries succeed the falling OF warm
rains after the mountains have become covered
with snow, thus causing sudden thaws in the snow
fields. Such an event only happens after the main
stream through the valley has already been moder-
ately high several times during the season from the
effects of transforms brought down by some Of its
tributaries.
The freshets of the greatest magnitude from the
mountain basin Of the sacramento and the tributa-
res which also enter the valley its northern
tremity are produced by sudden and violent storms
OF rain which ordinarily pass the region of the
tributaries further south cold rains Of short dura
ton and less violence.
There are then, in general terms, two sources OF
high water in the valley drains, each composed of
group OF streams which We must expect To be in high
flood simultaneously And at the time we
must look for moderate flood flow, in each in
stance, from the streams Of the other groups
This combination OF events produces what we may
call the ordinary high flood wave of the lower valley
such passes through the channel ando the
low lands once or perhaps twice each winter OF
spring, except in of drot ght occurring once
or twice every ten years.
When after several moderate storms during a sea-
son, there occurs violent and somew hat prolonged
storm succession OF rain storms Immediately fol-
lowed by quiet and warm rain, the SHOWS me t on
the mountains and great volumes OF flood waters
ter the valley from all the surrounding water sheds
at the same me, and thus are produced the extra
ordinary floods which have occurred periodically
about once every ten years in the past.
The river channels and more particularly the Sac
ramento as the main drain of the valley, being insult
cient in capacity for the immediate passage to the
bay of ordinary floods these waters have, for ages
past, poured over its banks and been temporarily
lodged in the low basins by which it is ianked for
miles of its course to be drained off after the pass
age of the flood wave proper.
The river has always been one of poor regimen
great variation of capacity pass the of flood
through its different divisions its channel has
always had serious local defects which have acted as
distractions to the passage of flood waters. Thus
for log miles and more above the head of Butte
Slough, there is a channel of greater grade and
greater dimensions than there is below all the way
to the mouth OF Feather river, distance of "a
miles. And again, the very shallow bars, known as
the Six Mile Haycock, Hog shack, Iron House, and
Newtown Shoals, do not permit the free pass sc OF
the flood waves as do the deeper and better formed
reaches of the channel above aud below them
Besides the Sacramento, the Feather is the only
other river channel which acts as main drain, and
is in that capacity auxiliary to the Sacramento
throughout the middle portion of its valley
course, receiving and leading down the valley
the waters of the Yuba and Bear rivers, as well as
those of other smaller streams, to the Sacramento
Of which it is the largest efHuent.
THE CAUSES FOR RECENT CHANGES IN THE
VALLEY RIVERS
These streams-the Feather and the Sacramento
below the junction of the two-have been greatly
reduced in fiood-carrying capacity by the Judgment
of sand in their channels which has come down the
rivers from the mining regions during the past
twenty-five years or more. The presence OF this
sand in the waters and in the beds of the upper nv
constitutes the present cause of the changes in
the channels OF the lower streams spoken Of; but
its precipitation and retention in the last mentioned
channels have been greatly increased by other
causes which are now to be mentioned
The attempts which have been made to keep the
food waters off the swamp and basin lands, by the
construction OF levees, have not been conducted
cording to any uniform plan, or upon any system
which could be generally sue ;essful.
The result has been in measure, satisfactory to
the projectors OF these works at some points in
ana larger territory, where failure partial
complete, is apparent.
By this unequal treatment, the natural order of
things-with respect to the regimen of the stream
has been mterfered with in measure to still fur
Their impair the capacity of the channel in the
several succeeding divisions of its course, to pass
the waters which are brought to it.
In the natural state OF the stream, the waters of
the Sacramento river, at times of ordinary flood,
just overtopped the banks = thus spreading in
small quantities in innumerable places along its
c0urse-and found vent into the basins (without
that material sudden checking of the current which
must happen when a large quantity of water is di
verted at one place., and the banks were gradually
and uniformly built up by the annual deposit OF
sediment thereon.
The construction of levees stopped the general
escape Of waters in the manner described and they
are now confined for comparatively long distances,
and then escape in large volumes through
or breaks which oc ur annually, or are LETT open
from year to year.
New divisions OF the stream into two streams, as
it were, are thus formed at many points; and as q
result OF such division Of waters the regimen OF the
main channel is disturbed, and its fioou-carryiug
capacity diminished by the shoaling which takes
place below each point of division, while the in
crea ed securing power which should be acquired
by concentration of the water is nullied in effect
by the irregularity Of the flow caused by the con-
siderable local losses OF water through the crevasses
The faulty location of levees, with respect to the
proper training OF the rent and to the shape or
teHG OF clannel, as well as with regard TO the
width space between those on the opposite banks
OF the river, has restricted the eectual water space
unequally in succeeding reaches of the river, and
producing inequalities in the movement of the flood
waters, by causing eddies, whrls and bars, has re-
suited in an elevation in the flood line, while the
increased securing capacity, which should be ae-
quired by concentration of floods between banks,
has been locally nullitied by this increased irregu-
larity of flow.
Certain cut-offs which have occurred during late
If hp
the riyer-between Colusa and Chico creek-while
they have hastened the drainage of the region above
them, have had bad effect upon the general regi-
men of the river by hurryiDg the waves of food
down upon the division below, which already OF
comparatively small capacity.
Thus in reviewing the situation we find that while
the works undertaken by individuals or combina-
tons of individuals into DISTRICTS each striving for
his or their own local interest," have tended to d-
minish the efficiency of the stream nothing what
ever has been done towards the general treatment
OF the river fiood-c carrying channel, drain in
the preservation and Improvement of which all have
common interest.
MINING DETRITUS AND THE VALLEY RIVERS
The connection between these drainage questions
and the debris problem " is so intimate, and the
satisfactory settlement of the former depends so
much upon an engineering solution OF the latter,
that it may seem proper here to discuss this last
mentioned subject, and elucdate whatever concu-
slons may be arrived at concerning it.. But this
would necessitate long and not altogether relevant
DEPRESSION from the main object of this particular
portion OF my report. Moreover, it is a subject
worthy of special consideration and will be treated
in separate paper under the title Of &c The Debris
Problem" Meantime, so far as this question affects
the river problems, now announce certain primary
conclusions respecting it. and ask attention to Part
8 of this report for a more detailed consideration
based upon such data have thus far been able to
secure.
Taking the streams through the valley, in the
condition in which their channels now are it is
within the scope of engineering work not only to
restore them to their former comparatively good
condition, but to make them capable of CARRYING
away very much greater momentary volume of water
than they ever have been able to provide for; and
this end can be attained and the improved channel
maintained, it is believed, at an expenditure of
money by no means out of proportion to the benefits
which will result from it, and the dangers to be
warded off.
But this cannot be accomplished at reasonable
cost on the lower rivers if the supply Of sand an
nually brought down from the canyons above by the
tributaries, ana liable to be brought do wn
upon the occurrence of of the periodical extra
ordinarily large floods, remains undimnshed.
The Gather river below the mountains and its
main tributaries, well as the American river in
their several through the valley ITSELF the
main canyons of these larger streams-except the
Feather-for considerable distances within the foot
hills, and at points well up in the mountains and
many OF the side ravnes tributary to all these main
canyons, are now vast reservoirs Of detrtus whence
will come for years in the FUTURE with each wave OF