WRIA 62 WMP 032305 - Washington State Department of Ecology

March, 2005 -73- 023-1289-003.3040
potential to limit population growth in WRIA 62 where domestic exempt wells may be the best
alternative or the only alternative for drinking water supply. The Planning Unit believes that
establishing minimum instream flows to support in-stream needs and to protect senior water rights
while also providing for rural development is a realistic and achievable goal.
The Planning Unit feels that domestic exempt wells are important to support rural development and
population growth in WRIA 62. As a result, the Planning Unit discussed the option of making a
recommendation to the Legislature not to condition exempt wells (as defined in RCW 90.44.050) to
instream flows that may be set in the future. This recommendation was strongly supported by some
Planning Unit members and strongly opposed by others. Since the Planning Unit operates by
consensus, this recommendation was removed from the Plan. Further discussion resulted in the
recommendation that in-house domestic use and normal stock watering from domestic exempt wells
drilled after establishment of minimum instream flow rules not be restricted by these rules. "In-house
domestic use" means use of water for drinking, cleaning, sanitation, and other uses in a residence,
excluding irrigation of lawn and garden. The Planning Unit acknowledged that about 70% of water
withdrawn by domestic exempt wells may be returned to shallow aquifer systems through a septic
system or via percolation (USGS, 2000). In policy, Ecology considers a 50% return flow.
In more rural watersheds such as the Pend Oreille, where public water systems are not available to
many residents, permit-exempt domestic wells are relied upon for most residential water needs. The
Planning Unit has attempted to plan for domestic exempt wells by setting up a framework that will
include evaluating instream flows, and utilizing estimates of groundwater and surface water
availability in sub-basins to develop a reservation(s) of water (per Chapter 590 WAC) to, in part,
identify future reliable sources of water.
Since Ecology has closed to further appropriation or placed low-flow restrictions on many of the
WRIA 62 sub-basins with insufficient stream flow gaging information to support the closures (see
Table 4-1 and Figure 4-3), the Planning Unit discussed the option of the Implementing Body
addressing instream flow studies proactively in order to quantify how much water is needed for
instream resources and to determine if additional water is available for future appropriation.
The Planning Unit agreed that if an instream flow study indicates water is available for future
appropriation, that the Implementing Body should consider placing this water within a reservation for
future growth (per Chapter 590 WAC). This reservation, since it is set considering instream flow
needs, would be senior to the instream flow rule and therefore would not be conditioned to the
instream flow. The Planning Unit agreed that it should consider instream flow setting in the subbasins
that are closed to further appropriation or restricted and in the sub-basins that are expected to
experience the greatest population growth. As illustrated on Figure 4-2, these are the Calispell,
Davis, Skookum, Kent and McCloud sub-basins. The types and amount of water appropriated in the
reservation would be determined by the Implementing Body based on how the Implementing Body
predicted growth to occur. For example, if growth is expected to occur primarily by domestic exempt
wells, then a reasonable amount of water (less than the statutory 5,000 gallon per day allocation and
considering water returns to the ground) would be applied to a domestic exempt well and based on the
water available, a domestic exempt well limit would be set for the geographical area covered by the
reservation.
At such a time when the reservation is close to being allocated, there will be a need to follow a
process to conduct more detailed water availability studies and/or to develop a mitigation framework.
More detailed water supply studies could address: hydraulic continuity between ground water and
surface water; development of an alternate water source (such as water withdrawal from a confined
aquifer or withdrawal from the mainstem of the Pend Oreille River along with treatment and
WRIA 62 WMP 032305