The Idaho Republican. [volume] (Blackfoot, Idaho) 1904-1932, 1923-01-11

Alpine to HeiSe does not appreciate
increase the loss already existin
and that this loss probably reap
pears as gain in the river beloy
Heise; also that the drop in tn
river discharge below 5000 secon
feet which produces net gain from
Alpine to Heise reduces the gail
from Heise to WoOdville by simila
amount. If it is concluded that tn,
water lost above Heise returns a
gain between Heise and Woodvill
| (and there seems to be considerable
evidence to support such a conclu
sion) then practically all the watel
from any source is available fol
diversion according to priorities
and neither storage nor natural flow
suffers any absolute loss, except by
evaporation.
The loss equitably chargeable tc
stored water for evaporation should
be based upon the additional area
flooded as result of carrying a
larger volume Of water in the river
Measurements have been made to
determine the increase of river
width due to the conveyance of 5000
second feet of stored water in
August at Moran, Alpine, Lyon and
Heise. The mean increase at these
stations is seven feet. The average
increase in width of the entire Sec
ton from Moran to Heise might be
greater, but fifty feet would prob
ably be liberal allowance. In the
distance of 1876 miles between
Moran and Heise, the additional
area flooded on this basis would be
$40 acres. The average evaporation
loss during August at Mud Lake in
1921 was .O2 feet per day, which if
applied to $40 acres gives a loss of
1874 acre feet per day, or 50 second
feet, which is practically insignifi-
cant considering the volume carried.
The section of the river from the
Heise to the Woodville gaging sta
ton is one in which there is nor
mally during the period of stored
water delivery net gain in the flow
of the river after taking due account
of increases from tributary streams
and decreases by canal diversions.
The One-half of 1 per cent loss
which it has been the rule to apply
in this section therefore was evil
IDENTIFY predicated upon the theory
that stored water could not gain in
and must, suffer a.
slight loss even if this loss be
limited to evaporation from in
creased flooded area. Early in 1919,
however, it developed that instead
If the usual net gain in this section
If the river an actual loss was evil
lent during the early part of the
stored water delivery period. In
with the advice and
of the advisory committee,
he method of computing transmits
ion losses both in this section and |
n the one between the Woodville
md Blackfoot gaging stations, was
eviSed in such way as to charge !
he stored water users with their
no rata of actual determined net
osses based upon the means of the
receding two days with a proviso
hat losses Heise to Woodville
hould never be less than half of
er cent. This method resulted in
otal loss to the stored water users
f between 13 and IA per cent from
he outlet of Jackson Lake to the
year of 1919. The same
lethod was continued during the
sasons of 1920 and 1921, but early
! 1920 it developed that because of
he more abundant supply of water
valuable, canals diverting between
lie Woodville and Blackfoot sta
ons in particular we're accustomed
, divert larger head than was !
,tually needed and to waste the eX- r
ass back to the river thru waste ,
avs. This had the effect of nullify- }
g to certain extent the computed !
sses on this section of the river, +
Id to compensate for this reduc- !
on, which could not be we'll deter ,
med without the actual measure +
ent of all the numerous waste n
avs, the total inflow from Black 4
OF river, which enters the river too II
r down for the upper valley canals
benefit from it, was credited to n
EN- together with all return flow q
lich was shown by the records. a
lring both 1920 and 1921 the !,
imputed loses were about 7 per II
Mt for the entire transmission o.
wn to Blackfoot, and as pre-
ously indicated, while the direct n
'ses were probably larger, the up i,
r valley canals had the benefit of q,
e Blackfoot river inflow as COM N
nsation. Two acts of investiga- m
ms. carried on during the season a,
1921 indicated that this was a re-
ry fair arrangement as between a,
? upper and lower valley water ri
srs, but did not properly segre- &C
tie storage and natural flow for
livery to lower valley canals. In
while retaining the =.
mer methods above the Wood ].
lie gaging station, a fiat loss Of 6 :
: cent has been agreed upon for :
)lication between the Woodville !.
Blackfoot river stations during
coming season of 1922, this loss
ng based upon the results of the m
} special determinations made sh
ing the season of 1921. Under br
S plan the flow from Blackfoot
er will be credited in the normal Fl
nner as inflow available to lower or
ley water users. CT
after reviewing all the evidence I'll
data available to the depart III
ut, it is my CONCLUSION that the pl;