(1) Ecology has weighed the public interest supported by providing a limited amount of water for domestic water supply against the potential for negative impact to instream resources. Ecology finds that the public interest advanced by these limited reserves clearly overrides the potential for negative impacts on instream resources. (RCW 90.54.020 (3)(a).)

Based on this finding, ecology hereby reserves specific quantities of groundwater for future domestic supply only. These reserves of water are not subject to the instream flows established in WAC 173-518-040 or closures established in WAC 173-518-050.

Consumptive water use that would impact surface water sources listed in Table III must be mitigated in accordance with this chapter. Reserves shall be debited when mitigation water is not available. Table IV shows the reserve quantities for each subbasin management unit.

(2) Conditions for use of the groundwater reserves are as follows:

(a) Access to the reserves shall be only for the purpose of domestic water use as defined under WAC 173-518-030.

(b) Water use shall meet all applicable local or state conservation standards and be consistent with the watershed plan.

(3) If a use from a reserve does not comply with all conditions of the reserves, ecology may take action under WAC 173-518-110.

(4) Ecology shall maintain a record of all appropriations from the reserves and will make this information available on ecology's web page.

(5) Ecology will account for water use from the reserves by debiting the calculated impacts to each closed surface water. The impacts to surface water are calculated as a percentage of the consumptive portion of estimated or measured water use. The debits to the reserves will be determined after consideration of any implemented mitigation.

(a) For a new domestic use served by an individual or community on-site septic system, ecology will use a standard consumptive amount of fifteen gallons per day.

(b) For a new domestic use served by a sanitary sewer, ecology will use a standard consumptive amount of one hundred fifty gallons per day.

(c) Impacts to the closed surface waters listed in Table III will be calculated using the 2008 Dungeness Groundwater Flow Model (Pacific Groundwater Group, 2009), unless, in the future, ecology determines a better method is available.

(d) Ecology may periodically adjust the amounts deducted from the reserves based on the best information available on actual water use.