The record-union., 1897-04-17

and passing through given cross-sec-
tional area, will require that same
oross-section no matter where it may
pass, when running with the same We
locity. The cross section of stream
and the main velocity of the water de-
termines absolutely the quantity Of
water that can pass through that cross
section and is equal to the product of
its area in square feet multiplied by the
velocity Ill feet per second. We have
seen from our discussion of the flow
of water through streams of various
widths Qn your issue of April 11th)
that the frictfonal area determines the
average velocity, therefore we will not
discuss that subject further.
1t must be clear, therefore, to our
readers that the same cross section
must prevail in the lower as in the up
per river, in order that, with the same
velocity, we may pass with safety the
body of water coming from it's source.
How, then, are We to pass this great
volume of water coming from the up
per portion of the Sacramento Valley
in flood season? There are two classes
Improvement that will enter into this
levees; the other the deepening of the
stream by lowering the elevation of it's
bed. They are coordinate workers
The one assists the other, and upon
these two kinds of work must we de-
pend for the improvement of our rive
ers. The width of the river must be
such that it will, with a given volume
of water, maintain as nearly as possi
bic a uniform channel. To construct
such a. channel from the imperfect
waterway that now passes through the
Sacramento Valley is no small task.
From our reasoning as to the best class
of channel, we must be convinced that
a radical change in the capacity of the
river must be made before it will even
approach the requirements of drainage
in the Sacramento Valley. By an ex-
animation of the
CROSS SECTION OF THE SACRA-
MENTO RIVER
AT the foot of K street, at Sacramento
City, we discover that the river bed has
been filled SO as to occupy over 1900
square feet of the original cross sec
ton of the stream as it was in 1854.
Since 1854, to keep pace with the in
crease in elevation of the river bed,
the land owners have leveed the river
so as to increase the area of cross
section on an average of about 1000
square feet. But while the land own
ers We're increasing it 1000 square feet
the filling in of the river bed and nee
essarily contraction of the stream has
reduced the 1854 cross section over
1900 square feet. Therefore, we have
lost no less than 5000 square feet Of
area in front of the city of Sacramento.
This indicates a loss of the capacity Of
the stream of not less than 10000 GU
bic feet of water per second.
BENEFITS OF LEVEES.
If the stream could be returned to its
condition in 1854 we would have, with
the levees we have constructed, in
creased the cross-sectional area about
1000 square feet, and therefore with
the 1900 square feet lost by filling we
would have a river containing not less
than 2S00O square feet of available
cross section in flood time. The present
available cross s-section is not more than
1000 square feet.
Now, let my readers bear in mind
that the quantity of water that can
pass a given point per second with
a given velocity and cross section of
stream is equal to the area in sqaure
feet multiplied by the average veloc-
ity of the stream. Therefore, if the
average velocity should be 5 feet per
second, with the present river we could
not expect to pass more than 10000
cubic feet of water per second with the
surface of the water at an elevation the
same as in 1889, when the gauge at
Sacramento City registered 81 feet
above low tide in Suisun Bay.
AS IN 1854.
With the same velocity and the river
bed returned to it's condition in 1854
with the present levee system, the river
in 1889 would have had a cross-section-
al area Of 2S,000 square feet and with
a velocity of ; feet per second would
have passed 10000 cubic feet per sec
ond. But with the increased depth We
may presume that the velocity will in
crease, and it would not be beyond
the bounds of reason and observation
to assume that the river would pass
not less than 10000 cubic feet of
water per second. We have no data
to state positively the flow of the
American River during flood seasons,
but from observations made by the
State Engineer in 1S1S-79 we may ap-
proximate its flow. 1t has not been
estimated at more than 10000 cubic
feet per second, and generally does not
exceed 25,000 Therefore averaging it
at 10000 cubic feet per second, the
Sacramento River, returned to it's con-
AZ 4
food-waters of the American and Sac
ramento Rivers at the foot of K
street in 1896 with 5000 cubic feet per
second to spare. and not one drop would
have escaped into Yolo Basin.
FLOOD OF 1896.
That the flood of January and
February. 1896, was more than
an ordinary flood the records of high
water amply show. 1t viii be remem-
bered that the water in Yolo Basin was
extremely high the inflow amount
ing to over 10000 cubic feet per sec
ond from the Feather and Sacramento
Rivers, while Cache Creek and Putah
Creek added their volumes of discharge
to the water in the basin. The passing
waters in the Yolo Basin rose so high
that it was not unusual to see the
water of the basin standing hard
against the river bank levee and only
two feet or four lower than the water
on the opposite side of the levee in the
river. 1t must not. however, be passed
without observation that all the great
basins the Butte, Sutter and Ameri-
cam had been reservoiring the waters.
as ii were, due to a defective outlet to
the whole system. Could this water
have been conducted to its final outlet
more rapidly as it approached the Yolo
Basin. the ultimate elevation of +be