The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1875-02-09
dredges have been at work for several months

l
| bed during the year are estimated as follows:
From channel near ship-lock, 1890 cubic
yards of sand; from Rockets reef, AT cubic
yards of solid rock from Rockets rect, .58S
cubic yards of broken rock; from channel
near Drewry's island, 1915 cubic yards of
sand and gravel from channel near Chesa-
peake and Ohio Railroad Company's wharves,
1000 cubic yards Of sand and gravel f.; from
Richmond bar, 73,416 cubic yards of sand
from Randolph's fiat (by city dreiges), 81, 42l
cubic yards Of sand and mud, and 29.03S
cubic yards by contract, equal to &c. ,459l
| cubic yards Of sand and matchmaking q
total of 172 1864 cubic yards of material re-
moved.
| In addition to the above the city dredges
have removed for the Old Dominion Steam.
ship Company 1922 cubic yards, and for the
James River and kanawba Canal Company
| 1,512 cubic yards-making total Of 176, 370s
cubic yards of material removed.
| Nineteen hundred feet of dyke.have been
CONSTRUCTED at Richmond bar and ZOO feet
at Randolph's fat These dykes a. designed
not only to regulate the width of the river
and produce a uniform velocity, but to hold
back the material dredged from the channel
and prevent its being redeposited 10 the
| riyer.bed. 1t is only so fast rs these dykes
are completed that we may hope for perma-
nent improvement in the river channel.
| There have been no freshets in the river
worthy of note since May. One in that
month and another in January rose about
ten feet above the usual level of the river at
Rockets reef The year has been favorable
for work, and marked progress has been
made in deepening and widening the chan
mel. The (reshets referred TO deposited some
sand and gravel in channels. previously en-
cavated, but not so as to seriously iBjure
navigation.
A survey of the river between the ship
locks and the lower end Of Dutch Gap canal
was made in the early part of the year by
MIR. William Popp, under the direction of
Colonel William z. CraighlI, United States
engineer, in charge Of the Improvement, ard
some of the results of it may be of interest.
1t appears that, as compared with the coast
survey in 1855, there has been no lDateria,
change in the depth of the river above War
wick bar in that time except where artiii.
ca channels have been eXearated. The
depth Of water on Warwick tar, where OBJ
strucLions were placed during The war, Is
from three to four feet greater.
At Drewry's Bluff a considerable SCOUT
has occurred, due to Il similar cause. 4 de-
posit of about three feet has been made in
the river channel below the Upper end Ct
Dutch Gap, due evidently TO tie opening OF
the canal. Trent's reach remains in about
the same condition. 1t appears from oDscr-
yatons made on the tides at the same time
that the mean rise and fall at Rockets reef is
now three and half tect-an increase OF
nearly five inches over that observed in 1855.
This increase is also due in the main to the
opening of the canal.
The present condition Of the river above
Warwick bar is as follows: There is shoal
spot about. 500 feet below Gilie's creek
which appears to he 800 feet long, with only
13l feet in it at mean high tide. Elsewhere
above Rockets reef there is channel with
15b feet or more of water to the ship.lock.
The channel through Rockets reef is from
l30 to $50 feet wide, with not less than 153
feet depth at mean high water. This
depth is continued from the reef to near the
Friedrich Company's wharf, but with q mar.
row channel. From this point to about 200
feet below the Chesapeake and Ohio Rail-
road Company's coal. l.wharf there is gen.
orally 14s feet in depth, but at a
few points there is less, the minimum OBJ
served being 12l feet. a dredge is now at
work on this stretch removing the sand de.
posted by the freShet in May, 1874. From
the point mentioned to below Randolph's
fiat there is channel with minimum depth
OF log feet at mean high water, and with 4
minimum width oil l20 feet, except at Il point
100 feet below the wharf of the James
River Granite Company, where there is q
rock in the direct channel about 100 by 80
feet, Oh which there are but from 103 to 81
feet of water. There is channel 50 feet
wide and of the proper depth around this
>t, oD1 lra1 i of nrl- ,,,,or
the proper width. =.
There is, therefore, practically, channel
fifteen and half ieet deep at mean high wa
ter, and twelve feet at mean low water from
Just below the coal-whart to the sea, and
from opposite the coa-wharf there is four
teen feet. 4 dredge is now at work extend
luz this channel of fifteen and half feet in
| dcpthsAo owards the city, and if not much
hindered by frcshets we may expect this
depth to be carried to the ship-lockS in the
next SIX months.
The depths, except where it is otherwise
mentioned, are referred to mean high water.
There are times, especially during the high
westerly winds, when the level falls consld-
erably below this mean, as it always does to
some extent in neap tides. In November,
during westerly wind, the level of low Wa
ter was two feet seven inches below the
mean low.water mark.
The deposits due to freshets will ever be
source of expense; but when the river is
once properly opened and its width and ye-
loclty regulated by dykes, this expense ought
not to be a serious matter. Probably no
other avenue to the city of fifty miles in
lei 9Th Except ordinary roads, can be main
tanned at less expense, while in capacity the
river exceeds them all. 1t is evident that
the channel above Warwick's bar has been
greatly improved in the last two years-tbat
part below Rockets reef is very great i'm
provement. There is no doubt that by con.
structing the width Of water-course its
velocity and consequent scOur can be aug
mented and the cohtractions at Richmond
bar and Randolph's fit, due to the dykes
although still untinishedl will tend to keep
open the channels already cXcayated. The
effect OF fresbets at these points will be
watched with great interest.
The proper regulation Of rivers is receiving
marked attention in many places, and al.
though much has been learned by observa-
ton and experience, yet it is admitted to be
one of the most difficult subjects with which
engineers have to deal. The regimen OF q
river should be changed only with caution
and after patient study, and even then it is
sometimes to retrace steps already taken.
The experience gained on other SIM
| liar rivers is in high degree en-
couraging for the improvement of the
James, and the mere limited expert
ence here certainly tends in the same
direction. | see no reason, says MIR. Whit
comb, why the predictions of your former
engineers as to attainable depth of water
should not be verified, or that when your
| .o,,,,oroo diamonds mnrp than this that tha