BOARD00547

• Board Meeting Date: 7/20/2004
• Description: ISF Section - Upper Gunnison River Water Conservancy District, Case Nos. 4-02CW294 and 4-03CW107, Injury with Mitigation Proposal
• Board Meetings - Doc Type: Memo

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A notable impediment to the enforcement of the Board's in-stream flow rights under .
current conditions is the lack of adequate stream flow gages. There is currently only one gage
for all of the stream reaches impacted by the augmentation plan, and TV understands that the
District has agreed to maintain that gage, as it has for the past ten years, as a mitigating factor for
the continuing injury. That single gage has not been adequate in the past, however, to allow for
full enforcement of the Board's water rights. In light of the fact that the District has offered no
mitigation for the possible injury resulting from the continued use of wells connected to the East
River Regional Sanitation District treatment plant, TV believes the Board should require the
District to install and maintain additional staff gages to improve the enforceability of the
District's rights in the future.

Additional gages are also necessary to aid in the implementation of the augmentation
plan. Under the District's proposal, augmentation water will be made available for release from
Meridian Lake Reservoir when the eWeB's senior rights place a call. Without gages, however,
it may be impossible to ascertain whether the eWCB is entitled to place a call or to determine if
the District is providing the quantity of augmentation water required by the augmentation plan.
If new gages are not installed, the augmentation plan should clearly provide that the Board is
entitled to augmentation water when it is reasonable to assume, based on the existing gage or
other sound data or modeling, that the in-stream flow rights are or will be injured.

Because of the lack of gages, the District has only been able to estimate the extent of
current injury to the Board's water rights, and based on those estimates, the District has .
determined the amount of water to offer as mitigation. If in the future it is determined that the
degree of injury is greater than currently estimated, therc should be a mechanism by which the
Board can reopen the augmentation plan to require additional mitigation. TV would recommend
that the water court retain jurisdiction over the augmentation plan for a period of fifteen years
and that the augmentation plan include a provision allowing the Board to reopen the plan to
require additional mitigation ifit is detennined that the Board's rights are being injured to a
greater degree than currently estimated.

The augmentation plan depends on the assumption that wells with on-site treatment result
in depletions of only 10% of diversions. While TV is aware that the division engineer has
employed this assumption in the past, given the importance of protecting stream flows, TV
would urge that the assumption be reevaluated. Additionally, even ifuse of these weIls does
result in consumption of only 10% of diversions, the eWeB should evaluate the quality of the
return flow and consider requiring the District to provide additional water to compensate if the
return flow is ofIesser quality.

Finally, to mitigate out-of-priority winter well depletions that result in injury to the
Board's in-stream flow rights, the District proposes to establish a "winter pool" of water which
would be available for release to the CWCB in the late fall or winter, when conditions permit,
even when the CWCB's rights are not being injured. TV is comfortable with the concept ofthe
winter pool, but feels strongly that the Board should be entitled to use the winter pool water at
any time and in any manner that the eWCB determines it will most benefit the stream
environment. Rather than mitigating injury, making larger releases in late fall prior to reductions .
in stream flows during the winter can be detrimental to the health of a fishery.

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