Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1880-09-04
TIL RIVERS AND BAYS.
FINAL INTERVIEW WIIE CAPTAIN EADs
BEFORE HIS RETURN EAST.
The Methods for Impounding the Debris
Reformation of the Rivers Protec-
ton OF the Bays and Reclaim
alton of Lands

: held with him by q number of prominent
citizens with reference to his conclusions re-
sulting from the investigations he had made
Of the rivers and the debris question. There
were present State Engineer W. Ham. Hall.
Hon. j. n. Young. Hon. J. W. Armstrong,
Hon a. 81. Rose, Commissioners w. H.
Parks and ". L. Knox, ]. II. Carroll, d.
Lubin, representative of the RECORD Union
and others. The subject of impounding the
debris, erection of levees, improving the
river channels, protecting the bays, ETC., was
very freely discussed, ard the methods for
accomplishing these ends explained by Cap
tain Eads, from which consideration of the
subject the following questions and answers
were preserved and are presented in the
form OF an interview by consent of Captain
Eads:
Question: suppose, Captain Eads, you
have completed your examination of the Sac
rameuto river wi h reference to It's improve
IN mt n oluien Of the debris problem :?
Answer have made a pretty thorough
examination of the river and its tributaries.
Q.-How far up have you exan ind the
Sacramento?
A-As far as Chico landing.
Q.-How far up the Feather river did you
A.-As far as Cherokee and Smartsville.
I might also add that l have examined the
Yuba, Bear and the Sacramento to It's mouth,
including Suisun Bay and the Straits of Car
quinez
Q.-What is your opinion as TO the proha
biiity Of successfully iupounding the coarse
material coming from the mines?
Al think it quite practicable. It will
take some money and some time, also. 1t
will take much less time to arrest the flow of
debris, especially the heavy part of it, than it
will to correct the channels Of the rivers
Q.-What effect will the improvement of
the rivers have upon the lands which efforts
are being made TO reclaim?
A.-When the channels OF the rivers are
properly corrected the reclamation of the
lands will naturally follow, to great ex-
tent.
| Q-How may this debris be impounded,
What methods would you employ to i'm
pound the debris?
A.-By the use of willows which grow in
the neighborhood where the debris Is to be
| inpounded. BY constructing dams for ar
resting the velocity Of the current by which
means the debris viii be thrown down from
the water as it it carried along
Q.-Can debris be arrested by the means
you propose, within the limits Of true econ
omy viii the benefits to be derived be
worth what it will cost, Or in other words,
! Will 1t be good investment?
! A-IHere IS 30 question about that. San
| Francisco and every city below the point
| where the debris comes into the river are
| deeply interested IN this question It must
/ be arrested, or you must give up the naviga-
ton Of the rivers, and the whole Sacramento
! plain itself, il you leS the hydraulic mining
continue. The cost OF doing the work is a
mere bagateils as compared with the re-
suits.
Q.-Have you any idea as to the general
cost for doing the work?
Al am very free to say that l believe
million dollars expended within the next two
/ years would so arrest this debris that small
| 1.-THE Of that sum per year thereafter would
serve to retain the benefit thereby derived
| Q.-Nhst Is your opinion as TO the perma-
nency Of the works you propose?
Alt Is the current which transports this
material. Now the current IS simply the fall
OF water from higher TO lower level The
| resistance which arrests the current and
which finally destroys it, if Of sufficient ex-
tent, Is friction OF the stream. The fail OF |
water from the higher to the lower level, so
far as gravitation IS concerned increases in |
velocity according to the distance it flows It /
is the friction of the bed and sides Of the |
stream, and any obstacles in it which |
retards the current Experience has !
shown that by The use of light willow |
or brush distinctions, through which the /
water passes, and which are much cheaper |
! than imperyious or solid dams, they have the |
power OF arresting the current, owing to the |
/ friction which they prodsce in the water and
/ by placing light willow dams or screens in !
| the canons at the edge of the foothills and
above, and planting willows on the shoals
upon the present deposits of debris, the cur
rent can be so arrested as to rob it Of the
sediment. These dams are made with a view
to obstruct. to retard, the velocity of the
current, and not as absolute dams to hold
the water. The water passes through them |
and the sediment settles among the Willows |
coon forming q compact and heavy body, so |
that there is no possibility Of washing them
away. As the debris increases upon them
they become entirely covered. No food could |
wash these structures out. By this process |
the water loses almost all It's burden Of sedi- |
,ment, bat a small portion Of the finest of it |
viii still be held and carried in the water. !
In time these dams viii become filed with |
material, and they will cease 10 be effective
from that reason. They viii then have to be |
built up higher, or new ones constructed at |
other points. As they are merely !
built upon the sediment the next |
ones sre not necessarily built at |
the same points, but wherever they viii do /
the most good. It viii be found that az the |
sediment settles and fills IN, willows will /
at oncs start to grow upon 1t, and viii Ia |
the state 81 nature aid the work in hand By |
tending to hold back the water, and thus I
where there are none to be seen at present, |
there viii be plenty at hand By yhe time they |
wiz be required for renewing the works. I
They grow exceedingly rapid and spring up /
of their own accord wherever An opportunity
is afforded By such deposit. When Won build /
these dams tie first deposit that comes viii !
fill up between the willows nearly to the t
TOP Of them and then the willows will /
spging up and grow about them. BY having /
q succession OF these oosnwork structures, or
dams, the water passes through one and Is I
held back anc partly Gagged, and some Of the /
sediment caused 70 be dropped. 1t then
passes, with less velocity from having been
DISTRACTED, to the next dam, and there IS asain
held back IN the same manner, and by this
process the entire sediment is taken from the
water, and the lower portion Of the river re-
lisyed from further filing up. The effect Of
these dams Is a filing 10 snd raising the bed
OF the river az their locality, thus forming a
basin above, and these become depositipg
basins for sediment, which is thrown down
in them FROM rttsrding the velocity OF the
current by the dams. After q while these
dams will fill up. The dams will then have
to be built higher, thus forming new basins
which viii also in time become filed, and
when the dams have been raised as hgh IS
DraGtlcAHlts BhiEia WIZ Attti 70 Nb Hutal
higher III, or at other localities. This whole
matter Of thus holding back the sediment or
debris in the mountains and preventing the
further filing up Of the river channel, and
consequent damage caused to navigation and
the valley lands, depends upon the relation
existing between The velocity of the cur
rent and the amount Of sediment carried.
! was surprised to find the statement
in the report OF Humphreys and
Abbott made some FIVE years age, tbst there
was no relation between the velocity OF the
current and the sediment carried by the
water. said that is most absurd. The re
locity Of the current is the cause OF the sedi-
ment being held in suspension. Such dec
laration as that made by Humphreys and
Abbott, was to declare that there was no re-
lstion between cause and effect, and | took
their own tables and showed them to hecon-
trary and the error they had fallen into in
making their computations upon the subject.
They had taken the sediment found in
single cubic foot of water running at q gwen