The record-union., 1896-11-27
RIVER IMPROVEMENT
AND RECLAMATION.
What the Commissioner Of Public Works and En-.
gineeB Have to Report

vations, either Of high or low water,
refer to the one datum, and that is,
mean low tide, Suisun Bay.
Permit us to say here that the work
done by Mr.. Hall and his able corps
of assistants has proven to be invalu-
able, so far as the study of river prob
lens is concerned. 1t laid the founda-
ton for ali future observations, and It
is only by the careful study of the
question that We can arrive at any def
mite conclusions.
BY the aid of the work of Mr.. Hall,
we were able to establish water gauges
at various points on the river, and thus
by a system of simultaneous Observa-
tions have determined the slope of the
flood wave as it passes down the Sac
ramento Valley. The profile and plat
accompanying this report will show
the elevations of flood waters Of vari-
Gus years. The great question to be
solved is, how to find a sufficient escape
way for the flood waters of the Sacra-
mento Valley? 1t has been suggested
by many persons that an artificial
channel through the MonteZuma Hills
will be the very best escape way. This
question we will discusss at the proper
time. but let us now consider the ques-
tion of improving the lower Sacramento
River with a view to making it the
main escape way.
THE LOWER SACRAMENTO.
The particular portion of the river
now under discussion may be regard
ed as the tidal portion of the Sacra-
mento, but the more important section
being that portion of the river shown
on profile and plat hereto attached. By
an inspection of the profile just named,
we observe the very light grade Of
high water or flood line from Collins
VILE to Toland's Landing, and even up
stream. as at a point known as Sta
ton 153, just below Wood Island.
At Station 153 we find from a careful
investigation of the bed of the stream
that the cross sectional area below the
line of low tide in Suisun Bay is about
81, $50 square feet; that the cross sec
tional area of the river at this point
during flood period is about 32,34o
square feet. making a difference of
9, 1S5 square feet between low water in
Suisun Bay and high water in flood
time
If we now pass on to Station 1So on
the profile, at the head of Wood Island.
river at this point to be 49, 16O square
feet below low tide, and $1,000 square
feet at flood time The difference in
Suisun Bay and flood water is there
fore. at this point, %, $40 square feet.
It is therefore evident that the flood
waters must raise above the lowtide line
at the upper station, so as to produce
13.455 square feet in area more than at
the lower station, in order that the river
may carry the same amount of water.
If we will now examine the profile here
presented, we see at one glance the
cause of this great change in dis
tance of about three miles. The river
bottom has been elevated or filled up.
The plan of the shore line indicates an
abnormal width at the upper station of
900 feet, whereas the width at the
lower station is $50 feet. We see, as it
ere. a mountain rising up In the bed
of the river valley on either side, but
no other pass than over this formidable
mountain. Let us now discuss the prob
able results of the
REMOVAL OF THIS MOUNTAIN.
We Will first assume that the water
slope in flood time shall remain as it
was on February 1, 1896, when the
gauge at Rio Vista registered y feet 3
inches; the gauge at Collinsville regis
tered feet, and the gauge at Ryer Is
land pump-plant registered IA feet 1O
inches.
The elevation of high-water line at
| that time was 11.3 feet at Station 1o3,
and 13J at Station 1s5, giving fall in
the high water slope of % feet in a dis
tanGe of 10000.
Now let US cut down the bed of the
river to q depth Of 20 feet below low
/ tide. all along the line from the foot of
! Grand Island to Station 153. Let US
/ further assume that we have closed up
| the channel to a width of $50 feet aver
! age cross section at half tide.
Then. according to well-known law
| OF hydraulics for computing the flow OF
| rivers, we could have passed at this
| point not less than 21S,670 cubic feet
O. water per second.
! At Station JOB we have a depth OF
| p. , feet below low tide.
What were the real facts in the case
| during the food of January and Febru-
airy, 1886?
| At this time Nhe 1st day of February
| 1866, we measured the flow of the pass
/ ing flood at a point about one-half mile
above Newtown Landing, where the
waters of Yolo Basin, Steamboat
/ Slough and Old River were in one
stream 1t was found by that observa-
ton that, while the gauge at Maine
! Prairie registered Is feet the gauge al
Ryer Island pump plant registered Il
! feet 10 inches, the gauge at Rio Vista
| l. feet s inches, and that at Coliinsvillt
s feet At this time, and under these
/ conditions, the velocity ard cross-sec-
ton showed that there was passing the
/ point of observation 1G3,3S1 cubic feet
per second, with an average or uniform
| velocity OF Al feet per second. The
same cross section with given waite,
| slopes. by Cutters formula, indicated
the passing of 1852 cubic feet oi
water per second. \ remarkable check
EFFECT OF DEEPENING.
Therefore, according to the first by.
pothesis, by deepening the river TO 6
| depth Of 20 feet below tide. and $50 fee
in width. we could conduct 3d. .2S3 cubic
Aeel Oh Nalei iiioic feI SeSoiid 1T ti'
| same elevation of flood time than w,
did during the last flood.
Again, If we would deepen the river t
20 feet below low tide, with q width o
900 feet on the bottom, and slopinl
sides 10 the present leyees and high lant
at the station OF observation. than W.
would have cross sectional area o
5.Sl6 square feet, velocity of y l.s fee
per second. and a resultant dow of 231
912 cubic feet per second. In othe
words with this class of river. and tn,