The record-union., 1893-12-08

I
ner remove the tailings from the reservoir
! without any obligation to restrain them
/ in their new position. Perhaps the scale
OF this work may be so small as to be un-
worthy OF notice, and perhaps il it should
! become important the courts would IN
/ terVene Dy Injunction"
The commission also considers in It's re-
port the extent To which hydraulic min
ing Will be resumed because OF the priv
| ileges accorded by the new law. On this
matter the report is as follows:
/ line commission has no means as yet
of estimating the number of applications
with which it will have TO deal. In 1880
more than 400 hydraulic mines were re-
ported to be in operation within the
| drainage area OF the Sacramento and San
Joaquin Rivers.
''rhe Assessors of the mining counties
reported IN 1880 over 100000 inches of
water used in mining. The State Engi-
neer's estimate of the quantity OF gravel
mined in that year exceeded 3S,U00,OO0
cubic yards. The amount of workable
gravel yet remaining is indeterminate.
! Competent authorities place it at several
| hundred million cubic yards.
1T is not supposed that the commits
/ sion will have to deal with all, or nearly
/ ell, of this great mass. But on the other
hand it is not possible yet to estimate the
! percentages to come under our control.
! Much depends upon the working of the
system OF control during the coming year.
sit is probable that increased expendi-
lures and the restrictions upon freedom
of operations involved by the new sys
tenn Of regulation may act to make min
| ing in many cases less profitable than
| formerly, thereby reducing the magnl-
tude of the output and the number Of ap-
plications."
Referring to the deposits of auriferous
] Il l.
| high on the western flank of the Sierra
Nevada, and the availability Of large cav
tiles in these channels made by the n.y.
draulic process in former years Tor reSer-
voir sites at the present time, the report
continues:
sit is true that these sites are not pro-
| fitably available for storage in quantities
at all approaching the contents as they
were in a state of nature. Some of them
may not be at all practicable sites Tor any
great amount of storage. This is due 10
the fact that often there is not fall enough
/ from the gravel to be mined to the level
of the reservoir site. A fall of at least 100
| feet to the mile IS generally necessary, to
enable the SlulceS to carry the detrItus.
Much more fall than this is used when
available. The fall diminishes as the
reservoir becomes filled. The limit of
! profitable mining may be reached before
| the best ground in the mine, that which
| lies lowest, is broken.
Under such circumstances the miner
has a resource in elevating the gravel.
This is done by using large portion of
water power TO raise the material to
higher level. 1t is practiced to some eX-
tent. 1t lessons very much the quantity
that can be worked in a given time by
| given water power. Nevertheless it has
been used to lift to heights as great as
eighty feet.
"A second point worthy of attention i'll
| the decision of the North Bloomfield case
relates to the condition of escaping water
wasted after it has performed its full min
ing duty. The court practically holds
that ii the sand and gravel be restrained
| it is not to be insisted that the residual
water shall be clear, the evidence proving
that the Iinely divided clay, which gives
color to the water, is nowhere deposited
in appreciable quantities.
Apart from these reservoir sites, and
from such natural sites as may fulfill
equivalent conditions of safe storage,
there remain for deposit the beds of nat
ural Watercourses. Storage here is not so
favorable. These streams are subject to
treshets. They have falls of many feet to
the mile. In some cases the streams in
freshet may be termed torrents. Two
cases may be distinguished: First, where
the barriers are OVertOpped; and, second,
where a separate channel is made.
"Overtall barriers are subject to dam
ger of destruction by violence of flood,
and, if built in wood, sure to decay in a
few years, so that sooner or later there
comes time when they no longer re-
tain material deposited behind them.
Independently Of these considerations
the equilibrium OF river bed of movable
materials, over which unequal fowage
occurs, rivulet at one season and tor
rent at another, cannot be regarded as
constant under these different circum-
stances. There is probably no constant
slope of equilibrium. 1t varies with the
tiowage.
"While, therefore, a barrier placed
across the bed of such a stream must re-
strain, it can hardly be said to restrain
all and perhaps not nearly all deposits.
The wider the bed the smaller the freshets,
and the thinner the hight OF oVertall the
more effectually will the barrier restrain.
"a modification, which passes the flow
age in separate channel and permits no
overfall at the barrier, relieves the struc-
! ture from the more imminent peril. Y ct
the water-course passes over and through
the reservoir and while the barrier so
| long as not OvertOpped may be safe, yet
| uncertainty exists as to the efficiency of
| storage after time, due to causes already
| mentioned. Moreover mining ceases. in
| time. The residuum remains. In what
! way Is HAUL dl u0CdJ VI dILlCU1dI CdIll-
| age to q restraining system to be re-
| paired? Ii the stream have little or no
natural drainage the case is simpler. The
gold mining industry is important in its
| bearings upon the general interest of the
| United States as well as upon local pros
perity, and the risk is so great that ill-ad
! vised restriction upon activities is to be
| avoided. On the other hand, the great
amount of material that has been handled
and stored by hydraulic processes to get
little gold makes the problem of secur-
| ing impoundment and of the protection
! of nayigable waters and adjacent lands of
| equal difficulty and seriousness. Be-
tween these opposing and delicate condi-
tions the commission has to risk its way"
MORE DAMS TO BE BUILT.
Alta meeting of the Debris Commission
| held on Tuesday license was granted to
| Wastau q Hughes to conduct the New
York mine by hydraulic process. a stone
dam has been constructed across Howard
Creek, in Sierra County, to restrain the
debris, and this construction is approved
by the commission.
The commission granted the Quincy
Water and Mining Company permission
| to construct four dams according to plans
submitted to the commission and ap-
proved. to restrain the debris from the
! Spanish Ranch mine in PlumaS County.
| This permission is more important than
anv other granted by the commission.
The mines on Spanish Creek are large.
Spanish Creek, which empties in the
! Feather River, is to be damned by
stone wall. Two log and brush dams are
| to be built at the old pits. and a third dam
/ flogs and brush viii be made TO restrain
the debris in dry ravine. If these dams
are built according to the plans license
| to mine will be issued TO the Quincy COM
pany.