Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1880-11-17
CAPT. EADS' REPORT
Icosrrsrsp FROM rInsr rAas.l


,arre year, according to Mr.. Hal, was about $780,
nm 600 cubic yards, enough to have covered one
hall Of the surface OVERLOOKED three feet deep. In
the present condition OF the Feather and Sacra-
roopto il would not be deeirabie to have this addi
tionsl quantity eddci 60 the annual Hoods When
ne channels of these rivers are finally corrected.
and remainder Of the foods gathered IL them,
the addition of these reserved waters, no Longer
loaied with mining detritus, instead "a beng hurt
f., would result, we have seen, in positive oene
fl by oonferring upon the river addtioua power 70
further 9ower it's ecdine, should tho exhaustion oil
the mines make & then desirable TO liberate them
These facts should not be overlooked by those who
uyild cure theee evils by stopping the process OF
hvflrauIc mining 1t L hardly TO DO supposed that
The expense Of maintaining the reserycir anu resu
latng the discharge OF such vast quantity oil water
Wet,ltl he incurred II the mines ceased TO use It
suIsBE BAY AND SAX FRAEcIsoo HARBoR.
as lA-ge areas Of shoals, which now moro or
less exposed az low water, must as result OF the
ey-rection u tho river, necessarily be built up to
very nearly the hight OF the natu al banks by the
deposits which will be removed from the shallow
channels, and &C macy deep pools existing below the
san5bars IN ire parts OF the river Hill be-
fllsd with the bar material moved, there 10 no
occasion TO fear that the mobilization OF the river
vii materially increase the amount OF deposit 40
eruiDS IN the bays in the lower part OF the river In
The slow process Of nzture uncontrolled by art Sui
gn Bay would gradually be reduced to the width OF
the river proper. nnd tho Bay OF 6an Francisco
would IN time undergo similar change But is
and foods which determine the magnitude Of sedi-
neatary channcls. Hence the rapid drainage OF the
valley, by increasing the forcs Of the fools, Will
promote the discharge q the sediment INTO me
ssysn sd unit tho greater part a il Is finally dis
charged there The sediment left in the water.
altar The construction OF the proposed works Tor ar
resting he mining detritus. va settle much more
siowly than that which. nov flows down, and must
make the injury to the bags very slow and remote
eccurresce-
INFLUENCES uFog THE TIDES.
with respect TO the Influence Of the tides upon
the lower portion Of the river it is only necessary
b say that the same laws VIC have been discussing
apply with equal force tp the motion OF tidal
waters In river channels. The inward and outward
aox OF the tidee will create sud maintain channel
IN proportion 10 tho maximum volume and slnpe OF
ta ebh tide passing through the channel. Hence,
where tidal basin Of great extent occurs, as at
PEI, Royal, Neg York aud San francisco, the chan
mel through which t is filed and emptied VIII DC
p7opo-tionatey large. and, as the denth add width
Of the river channel incTcQSes the tldat wafer VIII
With less fractional resist lncc, aud the volume
81 the ebb will be Proporticnaely greater. There
fore, the Improvement q the lever part OF the
rer channel progresses the force OF tne tdi action
VII increase and aid In maintaining such capacity as
the combined ln1usi &c OF the river toods and tidal
action, under better system Of drainage, will
sreate
AREEsrTSG THE MINING DETRirUs.
The method proposed by sir. Hall fer arrestins
explained by him, and is upon the same system
substantially "a that recommended bv the hiSss-
sipp River Comulissi for the Improvement of that
river from Cairo TO the head OF the passes. This
system hiss been successfully applied ct the mouth
Of the river and, more recently, at points on the
Missouri. Is is based upon the in:imatio relation
which exists bstweeu the velocity OF the current
md the quantity of sediment it carries. AS the
Slightest retardatiou of the current viii cause the
waeI 20 deposit portion Oh its sediment, 1t Ii pro-
posed 10 paee, on the Yuba river, open( Tor peIY!ou
b-ushd?ms across the lower cnd OF the canyons Out
OF which the detrius flows, where tue foothills are
5 mi'e or more apart. and where the detritus has
filed the valley from hi 20 hill. These dams would
be placed from TIVE hunsrGd 10 four hundred fee,
one below another, but would be interui tod at
such l-ts OF the valley as ere covered With densey
growing willows, They would be only three or four
rect higD, except where they would cross the chan
nei Of tbs river. Atsuoh places the dams would be
81 permanent construction go as TO oblierate
the channc. and spread out tho water moro uni
fornly over the sface On which the dams are ir-
tended 20 arrest the sediment. In this way the
frieoBal resistance Of the bed is increased, and es
the water passes through each successive dam, it's
velocity is reduced and tho heavier portions OF its
sediment accumulated between the dauis and In the
brush The water which finally passes OF will con-
tain ony tha lighter doritus, which can easily DO
carried BY tie river Each year new dams wouldbe
huii. upon the deposits thus accumulated, but as
The old ones would probably send forth growth OF
willows, the renewal Of tic oaus on the deposits
would DO less necessary each year. ln this way the
deposits would DO arrested ever an area OF two or
three miles in length, and 81 the width existing DO
tween the foothills. The coutinnaly incr casing
hight Of the deposits would soon the mass TO
RAISE the water in the valley above it, and thus add
10 is effect that OF settling basin. The willow
dams would be OF the cleapoet possible construc-
tou, and they would only need to be strong enough
IL stand in the rapid water without sustaining any
aPp.ec.abie head or hydrost1tic pressure.
METHODS OF TREATMENT.
T;is nie;hod of treatment would be modified at
oeT local ties 10 suit the conditions presented at
ga Il ccording to the judgment OF the State Engi-
nee- Below the areas on which the detEitus would.
be thus impoundcd the waters would &c Collected
BY cheap willow Constructions into one channel OF
an R proxiiaatcly uniform width, through which
they weuld be Carried to the larg etreaUlS Fhis
correction OF the smaller tributaries would soon
e. Ise them To despen tteir beds, aud render the
N Intenanee q the leveeS near them less and less
necessary.
fle correction Of the Feather and Sacramento
rivers would be effected rs similar methods, inodi
fed to suit The conditions presented az cach locality
Light brush dams or gtre3us would be constructed
across tire shoqis where tue rivers tPo wide, and
Oh Improvement III the general lis urlent would be
made a certain ptact6. In Goiag THIS willow spur
dykes and dams OF Stronger construction would be
used, ard in some cases loaded with stone or
strengthened with piles and the banks, where they
required protection, would be reverted with thin
willow mattresses. The closure OF the outlets would
be made with willow mattresses, earth and stoue
Other materials. The chief object Of these works
would be to eject an Improvement IN the alignment
OF these r1VCrs ana 10 bii! eitu cnaiiiiels 70 al
approximate uniformity with the width of the we'll
formed parts of them.
Fora more exact knowledge Of the character and
details Of the works suggested, and vi the localities
whore II is proposed 70 apply them, reference is
ma e to the appendix 60 this report. and 10 plans
and specifications prepared by Mr. Hall
CONCURRENCE or VIEWS.
In conclusion, beg 10 state that have carefully
read Mr. Halls reports this subject and think lac
hes treated it vita much ability. In tho main
concur with him IN the views expressed, SO far as
they affect the question of proper remedial s. stem
Of improvement. The schedule. hereunto attached,
addressed bv Mr.. Hall to Colonel siondell aud n.y.
aelf giving The localities and the general method OF
correction proposed az each, has been carefully cx-
anined hvme. and the soEerd Improvements th rein
suggested meet my approval. 1t is important that
the proposed corrections IN the lower part of the
river especially that at Steamboat Slough DO cem-
me8ced and urged forward rapidly as those above.
Ii The entire system be properly executed and fully
completed, as proposed have no hesitation in rs.
srting that the results viii be most gratifying aud
romsnorative. haze the honor to be, very respect
fuly, your obedient servant, JAS. q. lads,
Consulting Engineer.