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

the process of enlargement 1t Is believed, however,
that the whole work could be completed at cost
far within the limits OF immediate returns from the
benefits to lands in the Yolo basin, and immunity
| from danger of flooding the islands below. More
Particularly would this be the ii the waters If
| the Sacramento were also not permitted to enter
the Yolo basin, as they do now, through the Gre
vases above sacramento.
| Whether or not the material to be removed would
admit of the inexpensive manner OF construction
here spoken OF can only be determined by careful
examination OF the route with borings to test the
| subsoils
| Ii the streams raising their channels at
the points where it is necessary to divert them
might expect the canal bed to raise also and this
would be an unfavorable circumstance If, on the
contrary, the water can be taken out, on suitable
grades, where the natural disposition snow to cut
down, and carried Ill grades approXmating thereto
| then the outlook would be hopeful This can only
be ascertained by watching the streams through at
| least two seasons
| RESERVOIRS FOR THE CREEK FLOODS.
| To reduce the maximum flow OF these creeks, and
thereby effect saving in the SIZE of the canal it
may be thought the plan OF holding back portion
| oil their foodwaters by open dams in the canyons
might be adopted to advantage. W hat is said i'll an
appendix to this report on the general subject of
! this method of dealing with floods however should
| be remembered in this connection.
| Cache creek would be the tributary to this new
channel most distant from its mouth. This stream
| Is made sp by two principal tributaries one of
! which drains Clear Lake This lake is already
regulator upon the food Solune in its stream-the
| time Of delivery is set back and amount Of maxi !
mum flow is doubtless decreased. As it is now, the
freshets from the other branch OF the creek come
down rapidly, and are led away before there is any
large contribution to the stream from the |
Clear Lake branch which follows afterwards. Sup
pose, now, a reservoir dam were put In at |
some suitable point on the northern branch, |
and its waters held back like those |
OF the Clear Lake branch may readily |
understand how the uniting of the two floi |
volumes from the two streams, in that event made
to down at the same time instead OF in success
sion, would form freshet of greater momentary
magnitude than would otherwise occur if the addi-
tional reservoir had not been built, though
each Of these waves were reduced in volume itself
by the effect OF its particular reservoir.
This same argument would apply in considering
proposition to hold back the floods in Putah creek,
ii the two creeks were to be led away in the same
canal for by preventing the rapid escape OF Putah
creek freshets, might hold them that their
maximum volumes would be presented to the main
channel at the same time that the greatest flood
flow arrived from Cache creek, which Of course
would not only be bad economy, but might result i'll
disaster.
On the whole the proposition to lead the waters
of Cache and Putah creeks into Suisuu
bay, by means OF high grade canal
over the Montezuma hills to Montezuma
Slough, may be looked to as the ground work of
probable solution of of the most difficult prob
lens in the drainage of the valley, but its efficacy
Will depend largely upon what course of treatment
OF the case receive, as VIII hereafter
appear more fully and its possibility and cost can
only be determined after fuller examination than
the time thus far elapsed could pc NIT OF being
made.
But the plan of holding back portion of the
flood waters OF these creeks, OF either of them,
by means OF dams, either open closed constructed
in the canyons, is one of very doubtful policy,
though further investigation may show it to be, in
this particular case free from the grave objections
which there are generally to such works.
| hope to have the opportunity of reporting
definitely on this whole subject, when the lapse of
another season has given opportunity to judge of
the present action OF the streams in question: with
respect TO the movement OF their beds.
THE RELIEF CANAL.
project TO divert portion of the waters of the
river, at Grays Bend or knights Landing-the head
OF the lower region of fioods-and conduct them to
the bay the route heretofore described, has al {
ready been reported by the Engineer to the Sacra
mento River Drainage Commission, under date of :
November Is, 1879. :
The conclusions put forth in that report are here
and enlarged upon. +
First In the present condition of the drainage }
lines of the valley, the waters which regarded !
as surplus below the proposed point of diversion, :
cannot be put into the projected relief canal, be-
they enter the main channel below that point.
The point of diversion selected is itself the lowest
down the valley whence such canal could be taken
out from the stream, and maintained, for the reason
that thence to tide water the river is fanked by
low basins, ross which the banks OF the canal 7
n
projected work would not to relieve the dis
tricts below from danger OF flooding. \
Second-On the grade upon which it is possible to :
construct the canal four inches to the mile-its :
waters would not carry to the bay the materials
which would be brought into it by Putah and Cache
creeks which have grades Of four feet and over to
the mile and hence the main canal would be filled
up and destroyed. II
1t was also shown in this report that the cost of
the proposed work would be eXcessi7e but with that
point, for the present, have nothing to do. '
The second conclusion is reasonable and, to say =
he least calculated to weigh heavily against this
proposition, under whatever form it may
De considered. 1t should be remarked here, how
,Eer, that the r-ument does not apply as >
gainst the proposition heretofore considere ed, to
ivert the creek waters alone through high grade
anal for the that the channel for this latter
purpose could be put grade sufficiently great to
,eep itself clear, while that which has to tap the
liver cannot. -
The material brought down by these streams pos i
IDLY could b held back to great extent, for
iderable time least, by dams constructed in the 81
anyons and Iavines above. Whether this could be | n
ffected in degree so far as to relieve the waters
rom sediment render their introduction into "
he low-grade canal safe is very doubtful. Ii this
we're done We nigh. expect great erosion OF mate
il would take place in the beds OF the creeks them
elves, where their waters would be confined by
evees in their courses across the plains (and there
must be comparatively very heavy grades), which
Material would be deposited, when the velocity of !.
he waters was checked, in the canal OF low grade. y
Cache and Putah creek waters might be taken In
nigh grade canal, as heretofore explained to the
ut through the hills, and there Joined with waters
brought forward in low grade canal from the Sac :
amento river, from which place Of joining the COM
Dined volumes could be conducted through the hills
in the same cut on a sufficient grade to keep the
channel clear.
CONSTRUCTION OF THE CUT. Il
By this arrangement the high-grade canal and the D
cut through the hills could be constructed on the in
expensive plan heretofore spoken of and it is prob
able that the cost of the combined works-hgh- .
grade and lowgrade canal-would not exceed the !
cost OF the low-grade canal alone by the original
plan, wherein the creeks were 10 be taken directly
into it opposite their points of debouchment from
the hills More particularly would this be the case y
ii it neeessary-as it certainly appears to be
under such arrangement-to build dams to hold '
back the solid materials whch would otherwise ill
the low-grade canal.
Thus disposing of the objection to the relief I
canal, based on the ground that the creek water
sediments would destroy it, the proposition comes
I'D on its merits relief to the river.
The first conclusion of the Engineer to the Drain
age Commission heretofore cited is ba ed upon the
present condition of affairs in the river system, viz
That sufficient water enters the river channel
below the point Of proposed diversion, at time OF
ordinary high floods, to cause the flooding OF the
Yolo and American basins, even with the crevasses
now existing in the levees closed and hence the
canal would not far relieve the river below as to
warrant its construction.
1t has been herenbeore asserted that the eastern
Feather and the American-might {
|
mento below the proposed point of diversion
to overtop much of the existing levees, when
the upper Sacramento river was only at ordinary
winter stage This condition of affairs would prob
ably occur but very seldom. But, under present
circumstances, large accession to the waters IN
the Sacramento river below the mouth of Feather,
at times of ordinary high food, is received from the
Sutter basin-between the Sacramento and Feather
rivers This water comes principally from the up
per Sacramento river, and enters this basin at its
head as well as at points below, through
in the levees which heretofore have occurred almost
annually.
Coming down the YaIley by this short cut, after
the basin has been filed by the earlier ffeshets of
the season, the waters OF the higher floods are
precipitatey presented to the channel at the head
of its fifth diyision-the mouth OF Feather river
and thence on down there may be large surplus in
the river as it exists without il being possible
to decrease the amount by diversion where canal
can be constructed, namely, at Knights Landing,
which is above where the great supply OF water comes
in For be it remembered, that this supply is
drawn, as it were, from an immense lake
with free outlet, and if all of the water coming
down the upper river channel were diverted into