Imperial Valley press., 1919-10-28

AnUiddc, cant, OCT. ~, lJi3.
Board of Directors
Imperial Irrigation Di&teict,
Fl Centre, California.
IGCnt.gmcU:
In view Of the copy Of Mr.. Grun&ky's
report dated August % having been
mailed me by your office, / assume the
directors would like my views regard
ing the river and Alamo
In observing Yuma gage heights fol
lowing annual peak flow, we find the
mean water surface elevation to be no
! higher than it was during the years
| when Weirs were not constructed. Con
! IScqucntIyl, the weir that is now in, or
those previously built, are not the
cause Of water-logged lands on the
Arizona side Neither is the Weir
menace Subiecting them to overflow
/ over and above what they were sub
| jocted to when Weirs were not needed
Or built.
If we are not creating any unusual
conditions above the Weir and are
merely maintaining conditions as they
] were prior to natural river deepening,
then we are not obliged, or rather
should not be compelled to make ex-
penditurcs with the view of lesscning
! danger of overflow to Arizona lands.
Diversion Only
If the preceding is true, then our
problem is only one of diversion. To
divert all of the water from q stream,
! whether it be a farm lateral or the
| Colorado River, the flow to be diverted
must be obstructed at least to a height
equal to the depth of the stream. This
is true irrespective of how deep the
channel to which the water is diverted
may be.
Considering excessive sand now dur
! ing high water. We are obliged, in order
to maintain required cana! section, to
keep Our canal bottom below that of
the river. Otherwise, following floods,
our full requirements could not be ob
tanned The canal being filled during
1918 flood was largely the carse Of
water shortage in that year AID, rs
doubt, shortages occurring in previous
years We're also largely caused by the
canal being filled adjacent to the in
take. The filing of the canal section
during the early part of 1913 occurred
only Immediately below Hanlon and
above to the river Consequently, our
dredging problem is between Hanon
land lockwood gates. Work below
lIanlon is only second in Importance.
Canal Lower
| To prove to your satisfaction that
cur problem is above Hanlon. | caLl
Your attention 10 canal lowering that
has taken place in the past two years
Taking the season OF the year when
tae Valley is growing its main crop
and fun water diversion is essential
we find that the water surface immed
lately below Hanl2n is four feet deeper
in the ground than it was two years
ago. This, to me, shows excellent pro
gress and should be a direct credit t.
our dro rodSing operations.
The dredgc Imperial should have
been launched TO operate between Han
Ion and RockWood where it would have
| been of assistance to the dredges CalcX-
leo and BraWey. Work can be done
! far more cheaDly and effectively in this
location, since spoilS may be discharged
directly into the river and because all
of the machines would be practically
/ toge ther. Another decided advantage
is that between iIanlon and lockwood
our canal is the highest and the proper
place where space should be provided
for unavoidable sand inflow from the
river. However. some good viii be ac-
complished by working this machine
whctc planned. ] am confident That
unless "mothinG is found radically
wrong with. the equipment, the machine
should be in operation with at least
one SHIFT by October 20.
Tecolote Cut
AS regards the Tecolote cut / think
1.-The lowering to he accomplished follow.
ing its completion will be a benefit to
our diversion at Hanlon only if the
iriver channel below the Weir should
lower. 1t is essential that the canal
! bottom at our point of diversion be at
least as low as the river bottom. Any
depth that the canal is in excess of this
is necessary only for the purpose of
| having required canal cross section
| or storage of sands that accompany
! the annual flood and enter our canal.
| Depth in addition TO this will be of
value only to care for accidents in ou}
diversion that would require inflow OF
sands far beyond the average. In view
of this. the Tecolote cut is a factor of
importance depending entirely upon
whether on not the river bottom below
the weir Will scour down an equal
amount TO what the water surface is to
be lowered by completing the Tecolote
cut.
TO me the problem is not a dredging
problem so much as it is to find some
means whereby the bulk of the sands
may he kept from entering our canal
system. | am absolutely confident that
Il study of conditions adjacent to our
diversion structure can be made that
will bring results saving the district
many thousands of dollars.
Remove Sands
1t can be readily seen how easy it
might be to dispense with the need OF
4 large dredge by only eliminating a
small proportion of the leakage that
occurring day in and day out between
tho Hundreds of boards that are used to
control inflow. When we realize from
five to ten per cent. of solids is good
discharge for a large dredge, it is easy
to see how this amount of sand might
De kept from trickling through the
boards at lockwood Gate. | am conf