WSP10371

• File Number: 8111.805
• Description: Arkansas River Compact Administration - Keesee Ditch
• Basin: Arkansas
• Date: 1/1/1986
• Author: HRS Engineering
• Title: Keesee Ditch Change of Water Rights Vol 1 - Historical Operation of Kessee Ditch
• Water Supply Pro - Doc Type: Publication

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In stream depletion analysis, the length of delay for recharge to reach the
stream is' described by the "Stream Depletion Factor" (SDF) for a particular
location or distance from the stream. The SDF method was developed by the
U.S. Geological Survey for the purpose of determining the effect on a surface
stream res)Jlting from pumping of water from an alluvial aquifer. The SDF value
for a location in the alluvial aquifer is the number of days for a certain percentage
of the pumping impact on the river to occur. Essentially, locations close to the
river have a lower SDF value than locations farther away, meaning that the river
is impacted more quickly by nearstream operations than by more distant
operations.

To analyze stream accretions or return flows for the Keesee Ditch, the
SDF methoQ was used to model the effects of recharge instead of pumping. Plate
3 includes a series of SDF value contours for the reach of the Arkansas River
in the vicinity of the Keesee Ditch. It was derived from ,a series of maps of
the Arkansas River Valley published by the U.S. Geological Survey (Jenkins and
Taylor, 1972). The proportional areas of the Keesee Ditch irrigation system
which occured between these contours were measured and an average SDF value
assigned to each area. The amounts of monthly irrigation recharge, as determined
from the water budget analysis, were then proportioned in a similar manner to
simulate the distribution of recharge for the irrigation operations. The amount
and timing of river accretions were then calculated based on the assigned SDF
values.

Table VII includes the monthly irrigation returns to the Arkansas River as
calculated ,using the SDF methodology. The calculated average annual return
flow to the river was 2,020 acre-feet per year.

The net depletions to the river resulting from the Keesee Ditch operation
are the result of both diversions and return flows. Since the depletion effect
of diversiohs is essentially instantaneous, the net river depletions may be
calculated as simply diversions, as represented by Table V, minus returns as
represented by Table VII. Table VIII includes the calculated net depletions to
the Arkans!1.s River resulting from Keesee Ditch irrigation of the decreed 1400
acres. Positive numbers in the table are net river depletions while negative
numbers indicate months when return flows exceeded depletions. Averaged over

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