The Beaver-Camas Subbasin of southeast Idaho is a watershed of the Upper Snake River Basin. The watershed is the easternmost in a series of five "sinks drainages." The subbasin is dominated by both natural and human-caused flow alterations.

Data have been collected and analyzed to evaluate the scope of the water quality limiting issues on §303(d) listed and non-listed streams. Seven temperature TMDLs and one sediment TMDL have been developed in response to the data. Some TMDLs have been established for non-listed streams since water quality data show that there are exceedances of Idaho's water quality standards.

Stream bank erosion, reduced riparian vegetation, and low flow conditions are the causes of increased water temperatures in the subbasin. Riparian grazing is the principal source of temperature and sediment loading to the watershed. Elevated temperatures from reduced riparian vegetation and accelerated stream bank erosion have been exacerbated by an ongoing drought.

There are two §303(d) listed segments on Beaver Creek. Temperatures in the upper segment of the creek exceed the state standard and a TMDL was developed. Perennial flows are seldom seen in the lower segment; therefore, it is proposed to be de-listed for all currently listed pollutants and re-listed only as flow altered.

Camas Creek is §303(d) listed from its headwaters to its mouth (as two segments). Riparian grazing has contributed to bank erosion and elevated stream temperatures. Sediment and temperature TMDLs have been calculated to address the pollutants of concern in the upper segment. The lower segment of Camas Creek is intermittent and flow altered for irrigation; therefore, it is recommended this segment be listed only as flow altered. No TMDLs were developed for the lower segment.

Cow Creek is §303(d) listed, but is an ephemeral stream and therefore should be de-listed; ephemeral streams are not expected to support the same biological communities as perennial waters.

Dairy, East Fork Camas, Modoc, Threemile, and West Fork Camas Creeks are not §303(d) listed. However, stream temperature data show that there were major exceedances in Idaho's numeric temperature criteria in these creeks. Temperature TMDLs were established for all five streams.

TMDLs were not developed for streams listed as flow or habitat altered. The EPA does not believe that flow or habitat alteration are pollutants as defined by the Clean Water Act. Since TMDLs are not required for water bodies impaired by pollution but not pollutants, TMDLs were not developed for flow or habitat altered streams.