Publication Summary

This is a briefing paper on the Wenatchee Basin, comprised of WRIAs 40 (Alkali-Squilchuck), 44 (Moses Coulee), 45 (Wenatchee), 46 (Entiat), and 47 (Chelan).

The Wenatchee Basin is comprised of WRIAs 40 (Alkali-Squilchuck), 44 (Moses Coulee), 45 (Wenatchee), 46 (Entiat), and 47 (Chelan). Neither WRIA 40 or 44 have major rivers (other than the Columbia River which forms the border between them and is addressed separately below). The major river basins within WRIAs 45-47 are the Wenatchee River, the Entiat River, and the Chelan River (Lake Chelan). Each of the river basins is extensively forested with very low proportions of land in either agriculture or urban landuse. However, because irrigated agriculture is the norm and because of the outstanding quality of water coming from the mountainous headwaters, water quality impacts from agriculture are obvious in specific tributaries and are becoming more evident in the major rivers.

The Wenatchee and Entiat River both originate in federally owned forest land in the Cascades where forestry and outdoor recreation are the main activities. There are extensive orchards downstream, many of which draw their irrigation water either directly from the rivers or from surficial aquifers. The Chelan River is very short, originating at the south end of Lake Chelan and flow is regulated by a dam. The upper Lake Chelan watershed includes portions of North Cascades National Park while residential and agricultural development is primarily located near the south end of the lake.

Little work has been done by Ecology's EILS Program on surface water in either WRIA 40 or 44.