The record-union. [volume] (Sacramento, Calif.) 1891-1903, 1899-01-01

taken or in contemplation has been to
so direct the currents by contraction
of waterway and better channel align
ment that the resultant scour may
form and maintain a channel through
existing shoals where width is exces-
sive, and establish as nearly as posi-
BILE the requisite conditions for uniform
velocity for all stages of the river.
SYSTEM ENDORSED BY HIGH AU-
o-i bsd THORITY.
| Leveson Francis Vernon Harcourt
NJ A., Civil Engineer of Balliol Col
| lege, Oxford. in his history of River
Improvement in Europe" thus refers
to the improvement of the River Clyde
by jetties and removal of hard shoals:
In the middle of the last century, the
Clyde was such an insignificant river
that it was fordable on foot at Dunn
book Ford, more than twelve miles be-
low Glasgow, and there We're numerous
shoals higher up. In the year 1l13,
Mr. Goldbome commenced the system
! of contracting the river by jetties SO
that it might scour itself out to a
deeper channel; and he also. removed
hard gravel shoals by dredging or
blowing that which the current was
unable to act upon. In the two follow
ing years the channel across Dumbock
Ford was made seven feet deep and
300 feet wide by dredging; and in six
years later it was found that the nat
ural scour of the river had lowered it
to fourteen feet"
page 2S4) 1.-The lowering of the
low water line is the natural conse-
quence of regulating and deepening the
river, which has facilitated the ebbing
out of the tides
page 1863 ct is interesting to note
with reference to fresh water discharge
Of the Clyde that, whereas the mum
dation of the low-lying parts of Glas-
Cow was of frequent occurrence up to
1910, the improvement of the outlets
has put an end OF these floods"
Authoritative history of results of
river improvement were extensively
quoted in your last report and numer-
Gus instances cited on the Clyde, the
Seine and other streams, where per-
fected artificial means for correcting
alignment and directing currents, such
as the system now begun on the Sac
ramento and San Joaquin Rivers. have
so completely aided the forces of ma
pediments to navigation and reclama-
ton have been wholly eliminated.
Like beneficial results will follow the
introduction of similar river improve
ment here; for, if the Sacramento
River was once deep enough to permit
vessels of larger draft to traverse 1t
at the low tide, low water stages, 1T
must be evident that the various half
dozen shoals that now seriously i'm
pede low water navigation between
Sacramento City and Rio Vista are
largely, at least. made up OF recent
deposits whose increasing prominence
makes clear the history of their origin
and the cause of their growth.
Through the influence of the law
of gravitation, with water as a trans
porting agency, the sand and silt that
form the recent impediments to navi-
CATION and retard flood flow, have been
borne from above and found lodgment
at places where reduced slope or excess
sive channel widths occur.
A perfect system of jetties and train
ing walls would establish, as nearly as
may be done, a uniform velocity for
all stages of the river, remove the bars.
provide uniform depth of water suffi-
Gent for commercial needs and greatly
reduce the difficulties of reclamation.
HYDRAULIC DREDGERS.
The eminent fitness of the modern
hydraulic dredger to make cheap, even
phenomenal, excavation, is universally
~aoorr{1a1 uyhoro tho 1iff io low and