Water Resources and Channel Geometry of Birch Creek National Wild River, Alaska. Fairbanks District Office

Birch Creek is a clear-water tributary of the Yukon River in the interior of Alaska. Surrounded by rugged uplands with scenic rocky bluffs in the headwaters, the watershed has significant sports fisheries and a variety of recreational river opportunities. These attributes were recognized in a congressional designation of Birch Creek as a National Wild River on December 2, 1980. The Bureau of Land Management (BLM) began a water rights and instream flow study in 1989 to protect these free-flowing waters. An application for water rights, based on the hydrologic data collected from 1989 to 1994 (Kostohrys and Sterin 1996) and the resource values documented by Sterin et al., (1998), was accepted by the State of Alaska, Department of Natural Resources on January 11, 2001. There were five or more years of data included in the application, although one gaging site with less data was largely estimated from regression equations based on nearby gages. The BLM continued to collect water resources data from 1995 to 2000 to fill this void as well as to obtain 10 years of record. This report documents the data from the latter period as well as the statistical analysis on all data combined for the entire period of record. This analysis indicated that updating the instream flow application with the data in this report may not be necessary. Riparian surveys of channel geometry to determine bankfull stream characteristics were also conducted on Birch Creek and its tributaries. These surveys documented the peak floods and impacts of mining runoff, and were used to calculate regional equations for channel design in placer mining reclamation.