WSP06233

• File Number: 8143.800
• Description: John Martin Reservoir - Water and Contracts
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 12/1/1999
• Title: Report of the Colorado State Engineer - Concerning Accounting of the Operations of an Offset Account in John Martin Reservoir for Colorado Pumping - 1998 -- Part 2 of 2
• Water Supply Pro - Doc Type: Report/Study

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N Mr. Steven J. Witte, Division Engineer
(Xl March 11,1999
f\.~ Page 3
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to them, and then all the water will be taken by LAWMA until the rotation has been
completed. This rotational procedure will be modified when LAWMA acquires the Spady
and Waldrop shares.

4) Mr. Howland will record the daily flows attributable to LAWMA's ownership and
calculate the daily consumptive use and return flow credits.

We understand that Mr. Howland is presently performing this function. and we expect that
he will continue with it in the future. The consumptive use and return now credits will be
calculated on the LAWMA-Highland water that flows over the Highland Diversion Dam,
Obviously, the LAWMA-Highland water will not include that being passed to satisfy senior
water rights in Water District 67 or water that occurs in the river in excess of the total
Highland demand. Mr. Howland can make these calculations in m,uch the same way as is
presently done, but different monthly percentages will be used since the ditch will be
operated only part of the time. The attached table derives percentages that are appropriate
for this situation; it is similar to Table 6 in our April 30, 1998 memorandum which sets forth
the percentages that are presently used. The table is based on the average diversions into
the canal during 1950-93, with prorations by stock ownership and delivery and use
efficiencies patterned after the H-I Model. Rows 1 through 4 derive the water that would
have been delivered to the non-LAWMA owners under this proposal and the canal losses
that would have been required to make the deliveries. Rows 5 through 18 show a water
budget for the LAWMA-Highland water. Rows 19 through 22 show return nows from the
LAWMA-Highland water, and Rows 23 <lnd 24 show stream depletion. The monthly stream
depletion percentages in Row 24 range from 4.1 in February to 83.1 in August. We
propose to simplify the procedure by limiting LAWMA's use of the water rights to the
months of April through October for which a single percentage of 75.3 would be applied. In
this situation, it will not be necessary to account for winter return nows since the stream
depletions in November, February, and March exceed the stream accretions in December
and January. Volumetric limitations to apply to the total LAWMA-Highland water as
measured at the Highland Diversion D<lm are not more than 12,021 acre-feet in anyone
year and not more than 101,940 acre-feet in any 10-year period.

Please let me know if you have any questions or need additional information.

Sincerely yours,

HELTON & WILLIAMSEN, P.C.

#~.4-.;W'~

rDuane D. Helton

DDH/mlc

Enclosure

I cc: Hal D. Simpson w/enc.
,EJ. 4- Dale Straw w/enc.
I (::\') Donald F. Higbee w/enc.

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