| Off-Channel Storage Reservoir(s) |
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| The concept of an off-channel reservoir is that water from the mainstem Walla Walla River would be diverted and stored when in excess of
in-stream flow needs. This excess water could then be delivered to local irrigators in lieu of irrigation withdrawals from in-stream flows during
critical migration and rearing seasons. Water exchanged with the irrigators would be equal to the amount of water left in-stream (bucket for
bucket exchange). Water from the storage reservoir would be conveyed to an irrigation dispersal point for distribution. |
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| Water Exchange: Piping Water from the Columbia River |
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| The general concept for the Columbia River Water Exchange measure is to reduce irrigation surface water withdrawals from the Walla Walla
River by supplying an alternate source of water directly to irrigation distribution systems, thus leaving more of the natural flows in the river. The
alternate source of water for this measure is the Columbia River.
The water for the exchange will be pumped from a pump station located on the Columbia River near the mouth of the Walla Walla River. It will
then be delivered to a total of ten existing points of delivery (POD) operated by the Gardena Farms Irrigation District (GFID), Walla Walla River
Irrigation District (WWRID), and the Hudson Bay District Improvement Company (HBDIC). |
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| Irrigation Efficiency |
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| The intent of irrigation efficiency is to reduce irrigation water withdrawals from the mainstem in-stream flows of the Walla Walla River by
reducing irrigation water lost through inefficient irrigation practices, seepage and evaporation, consolidation of systems, or by reducing or
eliminating tailwater discharges. The quantity of conserved water would remain in the river attempting to meet the goals and objectives of this
study. |
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| Water Rights |
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| This measure would include possible acquisition of existing surface water and groundwater rights issued by the States of Oregon and
Washington, or transfer from willing sellers into trust for environmental purposes. As a result, more water would remain in-stream. |
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| Shallow Aquifer |
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| Multiple measures were evaluated through the shallow aquifer. They include recharge, storage and recovery, and recharge for protection
purposes only. The measure that was carried forward is recharge for protection purposes.
Shallow aquifer recharge (SAR) for protection of in-stream flows will be utilized so that in-stream flow levels are realized. There are numerous
losing reaches along the mainstem channel and, through recharge, the losses through these reaches will be minimized. |
