Watershed Management Plan - Mason County

Appendix
A Sub-basin Summaries
Hamma Hamma Sub-basin
The Hamma Hamma sub-basin is centrally located in WRIA 16, covers
117.5 square miles, and is comprised of 74.1 miles of extensive tributary
drainages and several alpine lakes. The vast majority (95%) of the sub-basin
is within the Olympic National Forest and Olympic National Park. Landuse
in the remaining 5% of the watershed is agricultural and residential and
is concentrated along the lower reaches of the Hamma Hamma River and
along Hood Canal. The population in the sub-basin (300 in 2000) is
concentrated in the town of Eldon located near the mouth of the Hamma
Hamma River (Golder Associates, 2003).
The Hamma Hamma River is the largest stream in the sub-basin. Several
smaller creeks and tributaries flow through the sub-basin, including
McDonald Creek, Fulton Creek, Schaerer Creek, Waketickeh Creek, Johns
Creek, and an unnamed tributary to Hood Canal (Golder Associates, 2003).
WATER QUANTITY
Total discharge of water from the Hamma
Hamma River sub-basin, including both
surface water (streamflow) and groundwater
seepage to Hood Canal, is an estimated
470,069 acre-feet per year (AF/yr). Of this
total, an estimated 689 AF/yr are allocated
as surface water and groundwater. A small
amount of water is also consumed via
permit-exempt wells, but the consultants
for the Technical Assessment were not able
to estimate it due to lack of data (Golder
Associates, 2003).
Table 6 summarizes the known information
on water quantity in the Hamma Hamma
sub-basin.
(Hamma Hamma River, Ecology Oblique Photo, 2001)
Table 6. Summary of Water Quantity
page 72 Final Plan for County Adoption – May 11, 2006