Department of
Environmental Quality

Subbasin at a Glance

Overview

The Lower Kootenai and Moyie watersheds remained in a relatively natural condition until the early twentieth century when miners, loggers, and ranchers began to settle in the area. In recent years, timber harvest and grazing have been restricted to the floodplain of the lower portion of the Kootenai River.

Excessive sediment in the subbasin comes primarily from road crossings and encroachment. Temperature is most affected by stream shading. Metals and pH exceedances stem from historic mining activity near the headwaters of Blue Joe Creek.

Water temperatures are an issue in the Lower Kootenai and Moyie Subbasins. An SBA and TMDL for water temperatures was developed in 2005; however, before the temperature SBA/TMDL was completed, the Kootenai and Moyie River Basin Watershed Advisory Group suggested it be incorporated into this TMDL.

An assessment of temperature data in 2002 indicates that all monitored streams in the Lower Kootenai and Moyie Subbasins exceed Idaho temperature criteria. In a situation where all streams, including un-disrupted streams, have numeric criteria exceedances, a special look at natural conditions must be taken into account. The Lower Kootenai and Moyie watersheds are located in the northern-most portion of Idaho at relatively low elevations. Throughout the state it has been demonstrated that water temperatures are most strongly affected by air temperatures, which directly relate to elevation.

Metals and pH are identified as pollutants for Blue Joe Creek. At the time of the initial 1998 assessment, Blue Joe Creek was void of aquatic insect life and was impaired. The source of metals and associated pH issues is the now abandoned Continental Mine. Through environmental cleanup activities, both DEQ and the USDA Forest Service have been working to reduce metals and pH loading over the last three years. All reasonable TMDL implementation activities for metals and pH loading are complete, and Blue Joe Creek is in a state of recovery. Therefore, TMDLs for metals and pH for Blue Joe Creek were not developed.

The 1998 §303(d) list includes the Moyie River, from the Moyie River Dam to its confluence with the Kootenai River. Excess sediment is the listed pollutant, and based on the 1998 determination, a TMDL would be required. DEQ does not have Beneficial Use Reconnaissance (BURP) monitoring data on this section of Moyie River, and believes the sediment listing decision was based on anecdotal understandings and information. DEQ has evidence that the listing resulted from a single fine sediment deposition event and that the stream has recovered since that event. DEQ recommends removing the Moyie River from the §303(d) list and therefore did not develop a TMDL for this river.

Blue Joe Creek, Boulder Creek, and Caribou Creek have also been removed as candidates for sediment TMDL development for the following reasons:

• Draft TMDLs demonstrated that current sediment generating conditions are better than those showing full support of the beneficial uses.
• Draft TMDLs demonstrated that current sediment generating conditions are better than those showing full support of the beneficial uses.
• Stressor Identification Analysis (EPA 2000) performed by DEQ supports removal of these three streams as TMDL candidates.

Streams and Pollutants for Which TMDLs Were Developed

Boundary Creek

Temperature

Cow Creek

Sediment

Deep Creek

Temperature, sediment

Subbasin Document

• Assessment of Water Quality in Kootenai River and Moyie River Subbasins (TMDL) (September 2006)