Washington Administrative Code
Title 173 - Ecology, Department of (See also Titles 197, 317, 372, and 508)
Chapter 173-518 - Water resources management program for the dungeness portion of the Elwha-Dungeness water resource inventory area (WRIA) 18
Section 173-518-085 - Maximum depletion amounts

Universal Citation: WA Admin Code 173-518-085

Current through Register Vol. 24-06, March 15, 2024

(1) All unmitigated impacts from the consumptive use of water from the reserves and impacts from implementation of ecology approved mitigation plans shall be debited against the maximum depletion amount for each affected subbasin.

(2) The maximum depletion amounts shall not be exceeded.

(3) No new use that would result in impacts to closed surface waters exceeding the maximum depletion amounts during the critical period shall be allowed. If the cumulative impact calculated for a subbasin exceeds the maximum depletion amount, additional mitigation must be achieved before new uses impacting that subbasin can be authorized.

(4) Ecology shall maintain a record of all appropriations that result in deductions against the maximum depletion amounts. Ecology will account for water use from the maximum depletion amounts by debiting the calculated impact 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 deductions from the maximum depletion amounts will be determined after consideration of any implemented mitigation.

(a) For parcels served by an individual or community septic system, ten percent of indoor water use is assumed consumptive.

(b) For parcels served by a sanitary sewer system, one hundred percent of indoor water use is assumed consumptive.

(c) Ninety percent of outdoor water use is assumed to be consumptive.

(d) 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.

(e) The amounts deducted against the maximum depletion amounts may be adjusted periodically by ecology, to reflect actual use based on the best information available.

(5) Maximum depletion amounts are associated with, and not in addition to, the reserve amounts listed in WAC 173-518-070. Table V shows the maximum depletion amounts for each subbasin management unit.

Table V Maximum Depletion Amounts Due to New Groundwater Appropriation

Subbasin Management Unit

Cubic Feet Per Second

Gallons Per Day

Bagley Creek

0.01

6,463

Bell Creek

0.0023

1,486

Cassalery Creek

0.0013

840

Dungeness River and Matriotti Creek

0.76

491,201

Gierin Creek

0.0109

7,045

McDonald Creek

0.003

1,939

Meadowbrook Creek

0.026

16,804

Siebert Creek

0.022

14,219

Statutory Authority: Chapters 90.54, 90.22, 90.82, 90.03, 90.42, and 90.44 RCW. 12-23-054 (Order 07-17), § 173-518-085, filed 11/16/12, effective 1/2/13.

Disclaimer: These regulations may not be the most recent version. Washington may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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