The record-union. [volume] (Sacramento, Calif.) 1891-1903, 1897-08-26

l
serving the interests of navigation ana
becoming as We'll an important factor
of relief to the flood devastated coun-
| try above.
In order to determine the character
of material composing these shoals,
series Of wells at irregular distances
apart have been bored to a depth of
| twenty-five feet (and in some instances
nearly forty) below the low tide eleva-
ton of Suisun Bay on fixed lines ex-
tending from the right bank out into
the channel for over 1000 feet, and
samples of each stratum in determinate
order secured, properly labeled and
presented for your inspection and guild
| ance.
Silt, sand and gravel strata of var
| liable depth everything a substratum
of clay that in very few places rises
to an elevation within eighteen feet of
low tide in Suisun Bay constitute the
shoals.
From the material as shown by the
map deljneating the character and
| depth of each stratum and more fore
IDLY shown by the samples themselves,
it is conclusively determined that a
considerable depth and portion of the
the securing force of the concentrated
| volume following the construction of a
| thorough jetty system from selected
points in the left bank, and extending
outward so as to confine the flow to
effective limits.
Though such system of jetties alone
would probably bring about no violent
or sudden Improvement to the river
o17o "a
injurious agencies now at work and
steadily aid the force of nature in open
ing, charging and maintaining an i'm
proved channel through the shoals.
In pursuance of said resolution
passed by your board, desire to name
the work as to its Importance as fol-
lows:
First-The reduction of the Newtown
Shoals to conform to a channel Of a
mean depth of twenty feet below low
width of 200 feet
| SeconG-The closure of the Hershey
and Butcher crevasses on the right
bank of the Sacramento River between
Elkhorn ranch and the confluence of
the Feather and Sacramento rivers and
the substitution therefor of a concrete
|
600 feet and with q crest or eleva-
ton five feet below the high water line
of January, 1896.
The Importance of these particular
works cannot be separated for by the
union of action of the two, I regard
the success of river Improvement.
A beginning, however, must be made
and 1 would very respectfully suggest
l.
be commenced Immediately and prose-
cuted to a successful termination. The
plan of Improvement / would recon-
mend will consist of a system of jet
ties assisted by such dredging as may
be found necessary to produce the re-
quired channel way. l would recon-
mend the construction of a system of
curtain jetties as shown on plan of
this section of the river placed at dis
tances of 500 feet apart and projecting
from the shore line on the left bank of
the present river to the proposed left
bank of the new channel The proposed
channel will have a surface width at
high tide of / 200 feet and should be SO
excavated and improved as to produce
uniform waterway of 10000 square
feet cross section below the line of low
tide in Suisun Bay.
From the indications of other sec
tions of the river, 1 am convinced a
waterway over or through the Newtown
Shoals of the dimensions above given
once established would remain practi-
cally permanent. The samples of ma
terials taken from the borings of the
Shoals indicate a very heavy sand de-
post bordering on to small gravel. 1t
will require the concentration Of all
the water power available to remove the
material by scour and might require
the contraction of the river channel
more than above indicated to accom-
plsh the work. For this and other
reasons L would recommend the use of
hydraulic dredge in conjunction with
the jetty system.
From an examination of the plat of
river at Newtown Shoals, shown on
maps of same herewith presented, it
will be observed that I have located
the proposed jetties 500 feet distant
from each other measured down the
stream. 1t will require seven lines OF
jetties varying from length of 800
feet at the upper point to length or
] $50 feet at the maximum.
/ would recommend as follows: Five
jetties composed of a single row of piles
driven to a solid foundation at least
five feet below the mean depth of the
proposed stream. At the west end of
each jetty, cluster of three or more
piles driven to a depth satisfactory to
the Engineer in charge and strapped
and bolted firmly to each other at the
surface. At the present shore line, a
| pll of in Uan
driven, to which cable shall be an
chored. Between the two extremes
of these jetties, single row of piles al
least twelve inches in diameter and
driven twenty feet apart from center to
center, and at such depth as the En-
gineer may direct.
To the pile cluster on the present
shore line, a cable Wire shall be secure
~ fastened and run thence at an ele-
walton of mean tide. passing through
an augur hole in each pile thoroughly
fastened and drawn to the same and
finally securing the westerly end of
said wire to the cluster on the proposed
shore line, thus tying each pile TO the
other and to each cluster. The cable
shall not be less than three eighths OF
an inch in diameter galvanized and
constructed of smaller cable wires. On
the upstream side of this row of piles
Will be placed a layer of fascines one
above the other extending the whole
length of the jetties and firmly fas-
tened TO each cluster. the fascines to
be constructed OF well-selected brush
bound in bundles with ordinary ball
ing wire, at intervals of two feet: the
fascines thus bound together shall be