Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1881-02-23

ii. Mendell, OF the United States Enpinee,
Corps, in response to Horace Davis resolu
ton calling for information as to the cause.
tending to diminish the tidal area of Sar
Francisco bay and lessen the tidal scour OF
the bar, aud thereby decrease the depth o.
the water upon said bar, and diminish the
value of San Francisco as a commercial har
Dor. Colonel Mendell first specifies the
natural causes, which are practically not sub
ject to control. He describes the
DRAINAGE SYSTEM OF THE RIVERS
Implying into San Francisco bay,
and shows how the rapid fall OF
their tributaries and the violence OF
the rains favor the erasion and transportation
of earthly matter from the mountains and the
steady conversion of the marshes into dry
land. The present extent of the marshes in
San Francisco bay, including Suisun and San
Pablo bays, is stated at 800 square miles
Mention is next made of the similar tenden
cies of hydraulic mining, and the report then
proceeds to consider the artificial causes, such
as the construction of piers and jetties, and
the utilization of State and city grants of
submerged lands.
Referring to the piers and training walls at
Oakland, Co iMendell says: THE tendency
OF these structures is to hold the material de-
posted along the Shore and therefore to con-
centrate in small area the effect which 9th
erwise would have been distributed over
larger areas. This effect can never take great
dimensions" He reports in regard to
THE APPREHENDED sHoALING OF THE BAR
Outside the entrance to San Francisco bay,
that comparison of the survey made in 1855
with the one last made in 1873 shows that the
bar has not retreated, and that the depth of
water on its crest has not been diminished
He therefore says it is safe to state that the
bar was as good in 1873 as in 1855. No sur
vey has been made since 1878. After dis
cussing the various features of the problem
suggested, Colonel Mendell concludes his re-
port as follows: 1.-THE foregoing description
o. the bar demonstrates that it is able to lose
great part of its advantages and yet remain
an admirable channel for commercial pur-
poses. At present this channel is eleven
miles wide. If we suppose the bar to move
shoreward until it is shortened to half its
present length, it is apparent that largely
diminished tidal prison might be able to
maintain over the shorter line the depth it
now maintains over longer. The depth of
the crest might be reduced to much narrower
limits than the one last named, and yet remain
an excellent channel and be maintained by
tidal area only small fraction of that which
now contributes to this result If we sup
pose the crest of the bar to maintain its
present position instead of retreating, the eff
feet would be diminished channel, result
ing from the filing of the interior of the bays,
to encourage the growth of existing shoals
and to form new shoals. These shoals would
channels to be maintained The result would
be practically equivalent to that to be pro-
duced by the retreat of the bar shorewards,
and between these shoals one or more chan.
nels would remain
THE ACCESS TO THE HARBoR
Under these circumstances although far in
ferior to the present conditions OF oonven-
fence. might still compare favorably with the
approaches to many of the great commercial
ports of the world. 1t appears to be newt
able that the interior bays must continue to
lose in area. The force of gravity works in
cessantly to that end. There is no compen-
sation in any other natural force. The COM
mercial necessities are in the same direction
Of nature. and may seem to be under COM
mon necessity TO less tidal area yet the ulti-
mate disaster appears to be remote in the
future. We are not, however, on that &C.
count delivered from an obligation to coun-
teract these tendencies nor are we powerless
to do so in some degree.
Colonel Mendeu proceeds to indicate
what steps should be taken without further
delay. as means of accurately determining
upon the best remedies Immediately after
wards. He recommends that new survey
of the bar be made forthwith. and that
periodical surveys, both of the bar and of the
shoals about the bay, be provided for. An
other subject for investigation is the relative
securing value of equal quantities of water
stored in different parts of the great bay.
This he says. would indicate in some meas
ure the consequences to follow from the loss
of the lower part of the tidal prison of Suisgn
bay, a result that may be near az hand. He
adds: "There seems to be some ground for
the opinion that the bar would not be greatly
affected by this result.
THE INFLUENCE OF HYDRAULIC MINING,
AS compared with what may be called
natural influences, would of course, be an
available topic for study in this connection,
as mining is subject to control The ques-
ton as to what extent the owners of sub
merged lands should be allowed to fill is
also important. These are not questions
that can be solved in day or year. Dur
ing the period given to the investigation thus
outlined, other points of inquiry will suggest
themselves, and in due time information will
be obtained sufficiently to demonstrate the
soundness or upsoundness of the deductions
now drawn from the incomplete existing
data"