C150150 Feasibility Study

• Contract/PO #: C150150
• Contractor Name: Lower Arkansas Water Management Association
• Contract Type: Loan
• Water District: 67
• County: Bent
• Loan Projects - Doc Type: Feasibility Study

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During times when John Martin Reservoir is in conservation storage, LA WMA would
develop a procedure for measuring its portion of the direct flow Keesee water rights in-stream or
divert its portion of the direct flow Keesee water rights at the Keesee Ditch headgate, measure, and
return those flows to the Arkansas River by means of an augmentation station constructed off of the
Keesee Ditch. The replacement credit for LA WMA' s direct flow Keesee water rights would be equal
to the volume of the water rights in priority multiplied by the following stream depletion rates.

April
May
June
July
August
September
October

80%
76.7%
78.3%
77.1 %
70.3%
63.1%
55.2%

In order to compensate for winter return flows, 3.75% of the consumable water attributable to
LA WMA' s portion of the direct flow Keesee water rights will be transferred to a winter return flow
sub-account for later book over to conservation storage on November 1 of each year. Evaporation
losses to the winter return flow sub-account will be made up on a montWy basis from LA WMA's
stored consumable water.

Additionally, Article II Account water attributable to LA WMA's portion of the
Keesee water rights may either be delivered to the Offset Account in John Martin Reservoir, released
from John Martin Reservoir for in-stream replacement purposes or transferred to other Article II
Accounts in John Martin Reservoir for replacement purposes. As stated above, consumptive use
credit for the Keesee Article II Account water will be based on the average annual consumptive use
factor of 64.9%.

F. Impact of Adding One-'Half of the Keesee Water Rights on the Yield of LA WMA' s
Portfolio of Replacement Water Rights.

As part of this study the yield of LA WMA' s portfolio of replacement water rights was
analyzed with and without one-half of the Keesee water rights in a montWy operation study that
covered the period of 1950 through 2005. Tables 1 and 3 present a detailed annual summary ofthis
operation study with and without the Keesee water rights in LA WMA's portfolio of replacement
water rights. The operation study was intended to replicate the actual historical river conditions
during 1950 through 2002. The period of2003 through 2005 were represented as dry years having
the same hydrologic characteristics as 1979.

The operation study assumed that 12 years of pumping occurred under full LA WMA
allocations prior to 1950 so that a full level of depletions from pumping in previous years was brought
forward into 1950. The operation study used historical yields of all LA WMA replacement water
sources; the Fryingpan-Arkansas Project and the Article II Storage Account System in John Martin

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