The record-union., 1896-11-22

oilS OQ LQe most peTp&U0& QO6SMOuS5
before the people Of the State Of Cali
fornia.
The answers to the various questions
propounded are far-reaching, involving
a knowledge OF all the conditions that
existed before hydraulic mining was
commenced, as well as a minute detail Of
it's progress and the effects 1t has pro-
duced In the many years that 1T has
been permitted to continue, and the
effect produced by its cessation in 1885,
up to and including the present time.
They further involve the question of
the effect of restraining dams, which
seem to be the panacea. offered by the
hydraulic miner, and the ever-threat-
ening avalanche to the farmer.
To give an intelligent and well-ad-
vised answer to any one of the questions
propounded would require the collec-
| ton of data in the field, which as yet
has not, to our knowledge, been OBJ
tanned. The only official data in this
office is confined to the very excellent
work of State Engineer William Ham.
Hall and his assistants. So far as the
work was prosecuted under that emf
nent engineer and his very eminent
advisers, Colonel w. H. Mendell and
James 3. Eads, it is Of the utmost i'm
portance. With the conclusion of the
labors of the State Engineer the in
vestigation of this question ceased, so
far as the State Is concerned We there
fore have no official data with which
to frame intelligent answers to the
questions asked, except as to the mat
ter above mentioned.
To answer all the questions pro-
pounded would require a knowledge Of
the slopes of the various silt bearing
streams in their mountain reaches,
the quantity of material now inn
pounded in the various mountain
gorges, and the slope obtained by vir-
tue of the flow Of this material. All
OF which is almost totally unknown,
except so far as personal observation
has been made with the eye and not
by accurate instrumental measurement
First-The first question is rather In
definite in construction, not having
stated whether it means the navigable
or nom -llavigable streams; but we shall
presume that it is intended to apply to
naviglable streams. AS al abstract
proposition, we may say that any i'm
pediment to the flow of silt or debris
into a stream, which is permanent, will
benefit or improve the river to the ex-
tent of its storing capacity. We are not
advised as to the character of the con-
strUction of dams as proposed by meas
ures now pending in Congress. At no
point on the nayigable streams of the
State are we informed of the approach
of any coarse mining debris into the
navigable waters thereof. On the up
per Sacramento River the gravel or
coarse material has washed down
stream as far as the town Of Colusa;
but, this not being a stream subjected
to the effects of hydraulic mining, we
shall presume that the question does not
apply TO this portion of the Sacramento
River. lit may be TRUE that a portion of
the heavy material from hydraulic
mines has entered the valley on the up
per portion Of the Feather River; Of
this, however. We have no Information
at our command to either affirm or deny
the proposition So far as our obseTva
ttons extend, the greater quantity of
material that has been deposited in the
navigable streams consists of light
sands and fine silt Just how far this
class of material can be restrained is a
question which no engineer can answer
without data at fIand showing the re-
stradning powers OF dams under the in
Vulnerable conditions that may govern
the case. It was determined by Mr..
Hall, in his observations of the Feather
River in 1878, that not less than 90 per
cent OF the material in suspension in the
waters of this river was deposited i'm
mediately upon the waters escaping into
Sutter Basin. But it must be remem-
bered that these escaping waters came
in contact with a larger surface of fr1c-
tional area, the velocity was inInedi-
ately checked, and the power of the
water to hold the material IN suspension
was at once very materially destroyed.
We may, therefore, conclude that a dam
in it's early history will inpound the
material just as long as it checks the
velocity Of the stream, and that II will
cease to deposit matter in suspension
IL proportion to the increase OF the We
locity Of the moving water. A dam will
produce this effect If II has the power to
retain its material until flied to the
crest; but as soon as the dam Is filed,
ing incline until the incline becomes so
steep as TO render it impossible for
either the material in suspension or
that rolling on the bottom of the streams
to remain on the incline, when it will
move on To some point where the resist
ance Of the power TO move the material
equals or exceeds the moving force or
impact OF the water. You will, there
fore, perceive that the utility of dams
viii depend upon their storing capacity
and the quantity of material required TO
be impounded.
Second-We answer the second ques-
"a cts set forth in the answer to the first
interrogatiye.
Third-ln answer to the third ques-
ton. we can see no reason why dams in
themselves, properly constructed on the
non -nayigable rivers, would injure nav
lgation or work an injury to the
streams; provided. they are not CON-
structed in the valley regions. Any dam
that would raise the bed Of the river
above the adjoining lands would proba-
bly, result IN new channel formations.
which might divert the waters to valu-
able lands, and thereby result In great
injury 10 drainage as we'll as to prop
erty rights
Fourth-We presume that the fourth
question has reference TO the days of
hydraulic mining. It would seem, from
an examination of Mr.. Halls report,
that he was dealing with an existing
condition, and therefore suggested the
best remedy hfs knowledge would direct
for a remedy OF the bad effect that
might be produced by continuation of