Review of Proposals for Improving Methow and Twisp Rivers for Anadromous
Fish Interim Report
June 2002 | document IEAB 2002-2
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Summary
The Independent Economic Analysis Board (IEAB) has been asked to
review a proposed project to increase in-stream flows and improve fish
passage in the Twisp and Methow Rivers. The focus of the review is
cost-effectiveness of the project, which requires that we compare the
project costs to costs of alternative approaches to increasing in-stream
flows. The proposed Methow Valley Irrigation District (MVID) project was
developed by MVID, the Yakama Nation, and others over the last ten
years. There are several variations of the project, but all are similar.
All options would exclude about 1,110 acres from the MVID surface water
service area. Owners of the excluded lands would be compensated. The
remaining lands would receive water from a rehabilitated surface water
delivery system. During low flows, diversions from the Twisp River would
cease and more water would be diverted from the Methow instead. There is
still uncertainty about how and when this exchange would be
accomplished.
The IEAB has reviewed published information, and initiated
discussions with project advocates, researchers, and others. Based on
the information available at this time, the IEAB cannot determine if the
current project option, or the other similar options, are
cost-effective.
Some of the reasons for being inconclusive involve the MVID project
itself. Some costs are still being determined. Instream flow amounts and
triggers (i.e., when diversions would cease) are still being negotiated.
There is insufficient information regarding potential hydrologic effects
of the proposed project. An ongoing USGS study of groundwater hydrology,
including assessment of canal seepage and return flow to the Twisp
River, and the study of in-stream flow needs established by the current
proposal, may help to resolve these issues.
In addition, any cost-effectiveness determination requires a clear
definition of the set of alternatives under consideration. The potential
cost-effectiveness of the MVID proposal cannot be judged in a vacuum. In
other words, against what alternatives are we considering the MVID
project? At the very least, cost-effectiveness of the MVID project can
be considered relative to 1) other alternatives involving MVID, 2)
alternatives to improve instream flow that acquire water outside of MVID,
and 3) alternatives that include other types of improvements in a larger
geographic area.
The IEAB has considered one option involving MVID: water acquisition
(leasing or sales) from landowners in MVID. Water acquisition could be
accomplished by surface water transfers, or by paying landowners to
replace surface water with groundwater pumping. A comparison of the
proposed project costs to the likely costs of a water acquisition
approach suggests that water acquisition might be cost-effective.
However, any water acquisition involving MVID poses legal and political
concerns. In the short run, water transfers from MVID are believed to be
politically infeasible, at least because water rights are uncertain. The
existing MVID board of directors, or the Washington Department of
Ecology (WDOE), would not approve a transfer. Recent attempts to
complete water transfers involving MVID have not been successful. The
current MVID proposal includes what is probably the maximum feasible
amount of replacement of surface water with groundwater.
Water transfers might be a cost-effective part of the project in the
future. However, approval by MVID's Board of Directors will still be
required. Since there is no upstream storage, it may not be possible to
change the time of use to the low-flow period. MVID has an unusually
high density of landowners and residences, which may increase water
acquisition costs. Feasibility of water marketing may also be limited by
the inefficient conveyance system. The improved conveyance system might
facilitate transfers by minimizing canal leakage, improving measurement
capabilities, and allowing more exchanges.
The Twisp River is subject to more adverse low flow conditions than
the Methow, and much of the remaining controversy in the proposed
project involves Twisp River flows. The IEAB has briefly considered the
potential for Twisp River flow restoration by water acquisition from
water users other than MVID. The amount of water diversion by all other
water users combined is about equal to the MVID Twisp River diversion,
and some of the other diversions are junior in priority, so the amount
of available water may be insufficient to accomplish the biological
objectives.
Finally, we cannot determine whether the MVID project is
cost-effective relative to alternative projects that would help the same
species within the larger Methow River basin, or the ecological province
(Columbia Cascade). We have not reviewed or considered the feasibility
or cost-effectiveness of such other, broader approaches. These
approaches might include new upstream water storage, other types of
habitat improvements, supplementation, and/or some other cooperative
venture. With uncertainty involving MVID, water rights, and continued
delays in implementation of major improvements, there is value in
considering other options that might achieve comparable biological
benefits.
In summary,
- No determination of cost-effectiveness is possible at this time
for a number of reasons;
- Political, legal and structural changes would be needed before
water acquisition within MVID would be feasible;
- Some water acquisition may be a cost-effective part of a long-run
solution.
The IEAB proposes to update the Council on these matters within one
year.
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