The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1877-12-19

INTERESTING STATEMENT FROM MIR. II. D.
WHITCO3IB. ENGINEER OF THE IMPROVE.
MENT-THE EXTREME: HEIGHT OF THE
WATER ABOVE HIGH TIDE-THE PLAN
OF THE IMPROVEMENT A SUCCESS, sc.
Is In reply to q request made to the Engi-
neer OF the Janes-River Improvement to
furnish us with q statement Of the effect of
the late flood on the work under bis charge,
Mr.. Whitcomb sends the following inter
esting communication, which will be read
with pleasure by all who are interested in
the work on the river: e.
RICHMOND, December IS, 1877.
Editors Dispatch: The following inform
may be OF sufficient interest to your Rich
mond readers to induce you to publish il,
and answers your inquiries: -.
The extreme height above high tide at
Rockets was 25.3 feet; at Richmond bar,
22.G feet; at Warwick bar, 300 feet; at
Drewry's Bluff, 1875 feet; at Kingsland's
reach, 1914 feet; at upper end Dutch Gap
cutoff. 14.5 feet; at lower end Dutch Gap
cutoff, 12.4 feet; at Varina wharf, 1915
feet; at City Point, % feet; at Westovcr
wharf, 1.S feet.
It was i feet higher than the mark of the
flood Of 1870 at Rockets. am informed
verbally by the City Engineer that this
agrees with observations taken above the
city. .,s - E
The following note from Mr.. Il. Z. Blank
enship gives the increased rise at Belle Isle:
"Tbe great flood Of 1870 rose to within
six inches OF the top OF one OF the head
gates, and at the office, 1,1G5 feet further
down the river, it came within 125 inches
Of the top of the floor. In the recent freshet
the water attained the height OF 90 inches
above the top OF the head-gates, and G9
inches above the office-foor. By actual
measurement, the recent freShet was higher
at one Of the hcad-Sates by 90 inches and at
the Office By 19 inches than that OF 1870" :.
From this 1t appears that the flood was
as much higher than that OF 1870 above
Richmond as below Richmond. mention
this because have heard that some persons
have thought that the increased rise at
Rockets was due to the wing-dams in the
river below. The wing-dams are built to
very little above the level OF high tide, and,
although they contract the 1oidth OF the river
up to that level, yet the area between them
is quite equal to the area the whole river
had ut that level before they were built,
owing to the amount Of material secured
out from between them by ireshets. I am
very sure the wing-dams caused no sensible
increase in the height OF the flood.
EFFECT OF TIE FLOOD ON THE RIVER IMPROVE
MEST.
The effect OF the flood on the part OF the
river under Improvement was beneficial,
but at three points there was shoaling
enough to be injurious to navigation. The
first was opposite Drewry's island. This has
been removed. The second was on old
Warwick bar, about 1000 feet below the
lowest wing dam, and practicable channel
at least fifteen feet deep at high tide has
already been dredged through it. The third
shoal is in. Kingsland's reach, about ten
miles below the city. This has in some
places but 13s feet on it at high tide.
The dredges will begin work on it to-
morrow, and will have about GOO feet to
cut to clear it out to 16 feet at high tide. /
suppose it will take from SeUen to ten days
TO make channel 100 feet wide. From the
upDer end OF Richmond bar to little below
it's crest this food had no marked effect.
The dams here were the first that were
built, and no freshet since January last has
materially changed the section Of the bar.
The channel is rounded out little, but the
area is not increased. In 1870 this bar
shoaled up to 105 feet at high tide, and
Trent's reach, which is in the bend OF the
river now avoided by the Dutch Gap cutoff,
was shoaled up to the same depth. Nolo
Trcnt's reach, which had a depth OF 13 feet
few weeks since, has ten feet at high tide,
while Richmond-bar crest has log feet for
70 feet in width, with nearly 16 feet in the
centre OF the channel. At the lower end Of
Richmond bari. E., at the red can-buoy-
there are 120 feet width, with II feet water,
and in the deepest part the depth is 1919
feet. ..s ..... ...-
THE DAMAGE TO THE WING-DAMS.
Down to this point the wing-dams were
uninjured by the food-theY were well
protected by hard material drcdged from
nearer the citv. Below this several OF the
unfinished dams were more or less injured.
The cost to replace these is very small; but
we lost, what is OF more value, the full
effect due to them. Two at the head OF
Randolph's fiat gave way in part; and In
the direct channel there are but 153 feet
water. In q circuitous channel there is a
width OF 100 feet, with 16 feet depth. Five
hundred feet below the direct channel is
100 feet wide, with 16 feet depth. and a
greatest depth of 9feet, and from this to the
end OF the shoal there are from 16 to 90 feet
depth, with ample width OF channel. Be-
tween this and the site OF the military
bridge ut Warwick the dams were greatly
injured. These. dams were covered with
sand, and il was intended to cover this with
rock dredged near the city. This was done
only to limited extent for want OF money.
The lower two, however, stood better.
These were built to reduce shoal having
about 10 feet depth on it. We did some
dredging there in November, partly to get
material for the dams and partly to deepen
the channel to 16 feet. There are now %
feet depth OF water, and the channel for 16
feet depth is 400 feet wide.
The flood had no effect on Rockets reef,
of course, unless it may have lodged oD'
structions there; and over the reef, rhlch
lies belo,o all the city loharveS. there are but
about Il feet OF depth at mean high tide
as before the flood.
THE PLAN OF IMPROVEMENT A SUCCESS.
The result Of this flood only confirms me
in the opinion, which | have often eX'
pressed. that the plan Of improvement vii
be a permanent success. The Hood has
taught us where the lines OF contractor
need revision, and the changes needed te
secure IS feet depth on the sdnc-6dfS are
inexpensive.
Nayieators will find the best water neal
the black buoys, on Warwick bar. and near
the red buoys in the channel below the
Chesapeake and Ohio railroad wharves
Elsewhere I know Of no change in the
channel worth attention. In this remark
refer to the river from the city to WarWicA
bar, and not below that point.
Very respectfully, your obedient servant
II. D. WHTCONB.
ELECTION OF OFFICERS the regular
meeting OF the officers and teachers OF Pine