Watershed Management Plan - Mason County

Sub-basin Summaries
Appendix
A
permit-exempt wells; total estimated residential demand is 143 AF/yr. In
2010, an estimated 31 more people will live in the sub-basin, increasing
projected residential to demand to 148 AF/yr (Golder Associates, 2003).
Six applications for groundwater and one application for surface water are
currently pending in the Finch/Lilliwaup sub-basin (Golder Associates,
2003).
WATER QUALITY
The Department of Ecology listed Finch Creek as an impaired water body
due to fecal coliform levels above state water-quality standards. The exact
cause of elevated fecal levels has not been determined; however, possible
causes include failing septic systems and pet waste (EnviroVision, 2003).
Stormwater drainage near Hoodsport may also impact water quality in the
lower reaches of the sub-basin and Hood Canal. Ecology listed Lilliwaup
Creek as a water body of concern based on measured levels of fecal
coliform. More data need to be collected to determine if the Creek is
impaired and needs a water clean-up plan. However, the fact that the
Department of Health has closed shellfish harvesting in Lilliwaup Bay
(Washington State Department of Health, 2005) is likely indicative of
elevated fecal coliform levels in Lilliwaup Creek.
HABITAT
The Finch/Lilliwaup sub-basin supports many salmonid species including
chum, coho, chinook, and pink salmon, as well as cutthroat trout and
steelhead. Anadromous fish populations are generally limited to the lower
reaches of the sub-basin because of natural barriers (waterfalls and
cascades) as well as artificial structures (e.g., the hatchery intake structure at
mile 0.3 on Finch Creek). Habitat quality in the sub-basin is similar to that
in other WRIA 16 sub-basins. In general, estuarine degradation and loss of
riparian vegetation limit habitat quality for anadromous fish in the lower
reaches of the sub-basin. In the upper reaches, resident fish are blocked by
culverts or other barriers on several creeks, including Jorsted Creek, Eagle
Creek, upper Lilliwaup Creek, Little Lilliwaup Creek, and Miller Creek.
Other structures also block transport of woody debris and sediment,
including two culverts at Highway 101 along Ayock Creek and Little
Lilliwaup Creek, a hatchery intake structure at Finch Creek, and a 20-foot
dam on Hill Creek (WCC, 2003).
ISSUES
Based on the existing technical information in the Finch/Lilliwaup subbasin,
the following key issues emerge:
• Fecal coliform levels in Finch and Lilliwaup Creeks have exceeded
state water quality standards, but more data are needed, particularly
in Lilliwaup Creek;
Final Plan for County Adoption – May 11, 2006 page 77