The record-union., 1893-11-21
BRUSH OR RIPRAPS.
DR.. Dixon Addresses the Trustees on
the Subject.
He States That the Government Has
Abandoned Granite in Favor
of Brush Mattresses.

t0reSG 10 the ClLlZeDS OF SdcTatleHIO. l6
had no ak to grind, and presented simply
from the standpoint of citizen and a
taxpayer. AS the board knew, he had for
some years held the position of Chairman
of the River Improvement Association,
and when about two years ago engineers
came out here to investigate the condition
of the rivers of the State, he met Captain
Mckenzie, who was in charge of the
work. Knowing that the Captain had
had much experience in connection with
the Mississippi River he asked him some
questions about riprapping and granite
revetments.
Captain Mckenzie stated that after rip
rapping for years the Government had
abandoned the system long ago and TAX
ing to using brush mattresses. The Mis-
sissippi, Missouri and Sacramento were
all streams which carried a large amount
OF sediment. They had shifting channels
and sand bars and caving banks, on ac-
count of the instability of the currents.
The Government found by experience
that the current washed out beneath the
granite and let it slide down into the
river beds and had abandoned it, especi-
ally as the brush mattress, which was
far better, only cost one-tenth as much.
While he was at the Columbian Expo
sition he again met Captain Mckenzie,
who was there on behalf of the Govern
ment to show to the people its mode Of
dealing with the river question, and he
took an object lesson from his ap-
paratuS, which showed the manner OF
constructing brush mattresses to prevent
the caving of river banks. On his re-
turn home he found on his place a ne
Of llxy ct rat ha
usefulness of his lesson and it worked
like charm, there having been no
washing or caving there since. He con-
structed there a brush mattress forty
feet wide by 100 feet long, from brush
cut on the place, for $50.
The doctor presented map made by
Engineer Grunsky in 1851, showing the
condition Of the river bed for 500 feet
above the railroad bridge, and the
changes of the bed in various years. 1t
showed the bottom of the river close to
this shore at that time to have been sixty
feet below the top of the levee, while it
was shallow on the Y Yolo side. Now, it is
reversed.
Captain Roberts, he said, offers, if the
board wishes to put in brush mattresses,
to tow up as many barges as are needed
TO the proper place and leave them there
for use in putting in the mattresses, and
without cost to the city. He asked the
board to give Captain Roberts an oppor-
tunity to carry out his offer. The day for
riprapping has gone by, just as it has for
cobbles III the streets of sacramento. He
had letters from Manson and Grunsky
indorsingI the mattresses. If the board
would be in session in the afternoon, he
would go to the State Library and make
some estimates. He thought brush
mattress could be constructed 800 feet
long by forty feet wide for from $500 to
81 900.
The board decided to meet the doctor
in the afternoon.
In the afternoon DIR. Dixon addressed
the board again, saying that he had ex-
amined the matter at the State Library as
we'll as ne could in the limited time, and
the case of Memphis was the best exam
pie of a parallel case to the one under dis
cussion. Several hundred feet of the
bank were threatened by the erosion of
the undercurrent. A brush mattress was
put in and no further trouble was expert
enced from the erosions.
He had made an estimate, which
showed that the cost of brush, laid, was
$3 per cord, making Us cubic feet OF mat
tress, one foot thick. 1t would tal1e one
cubic yard of stone to weight the mat
tress. which could be made in sections
and sunk. He estimated that $40 feet
would cost $1,000. The brush is cheaper
here than in the East. Captain Eads, he
said, told w. +. Knox the same thing
with regard to granite riprapping and
brush mattresses when he was here. The
speaker was not talking against contract
ors, but as to the merits of the two plans.
p. a. Miller said it was not a new
thing. He had put in brush mattresses
fourteen years ago on the other side of the
river. He had much experience in that
sort of work and would support the
doctors statements. Where rock had
been used on the river bank it had
washed oute behind it III some instances
and LETT the rock twenty-five or thirty
feet out in the stream. The mattress has
been tested and proved itself good
thing. He preferred fascines, which
could be thrown in on the bottom and
weighted down, The sand soon fills
them and they anchor themselves. He
would make two rows of piles and fill in
between them.
DIR. Dixon thought piles a bad thing for
the river. With the mattress put into the
bank and weighted down, the sand soon
made it solid by filling it in. Then the
willows will take root, and in few
years you have a thicket-a living wall
that will put a stop to all cutting OF the
bank.
Mr.. Boyd thought the situation differ
ent here from that of the Mississippi
River. The mattress below the low
water line would be almost permanent
thing, while that which was exposed to
the action of the air and sun would dete-
riorate by exposure to the air. The ero-
sion is not, as in the Mississippi, at the
bottorn it is at or about the top of the
water. His idea was that if the stones
were properly put in, they would slide
down to the bottom if it was cut away be-
low them. He had made sections of the
river, and found the channel twenty or
twenty-five feet from the bank.
Dr. Dixon said that he had the greatest
respect for Mr.. Boyd's opinions, but a
map of the river. made by Mr.. Grunsky
a number OF years ago (in 1854, showed a
channel sixty feet deep from the top of
the levee, and what was there now is not
the true bottom of the river, but is silt
and is not stable. II the true bottom of
the river could be reached by the rock it
would slide down as Mr.. Boyd said, and
would make the most permanent protec-
ton, but at present il could not get to the
bottom.
Considerable more discussion of the
subject was had, and then on motion of
Trustee Green all the bids received last
week for making the mattress were de-
clared rejected.
Trustee Conklin thought the best plan
would be to engage competent man who
had had experience in the proposed
work, hire lot of men and get to work
as soon as possible on the job.
The Mayor thought that it would be
we'll to set some limit on the amount of
work to be done and not go at it hap
hazard. Some plans should be made to
guide the board.
Trustee Green thought that the City
Surveyor could get up some plans for the
guidance of the board and have them
ready by tomorrow.
Mr.. Boyd being called, said he could
have them ready by p. NJ. to-day and it
was settled that the board meet then.