Title
Watershed Assessment of Griffin Creek -- A major source of phosphorus to the Clark Fork River
Abstract
Gold Creek has been identified as a major source of phosphorus to the nutrient-impaired Clark Fork River of western Montana. This watershed assessment is a follow-up to a study that found that the primary source of the phosphorus in Gold Creek was one of its tributaries, Griffin Creek. Selected aspects of Griffin Creek’s water quality, riparian and physical condition were studied to document current conditions and identify potential sources of impairment and restoration needs. Riparian assessments involved riparian vegetation and streambank stability surveys. The physical assessment documented substrate composition, channel morphology, in-stream temperature fluctuations, and stream discharge. Water quality assessments addressed nutrient and sediment levels and loads at two sites on Griffin Creek and seven other sites throughout the Gold Creek basin. The upper reaches of Griffin Creek were dominated by beaver ponds and showed healthy riparian vegetation and stable channel conditions. The lower three-fourths of Griffin Creek exhibited riparian and channel conditions damaged by grazing, flow manipulation, and beaver dam removal. Griffin Creek continues to be a major source of nutrients to Gold Creek and exhibits nutrient concentrations that exceed water quality standards set for the Upper Clark Fork River. However, Griffin Creek is unlikely to be impaired by nutrients since its fine substrate will not support massive algae growths. Recommendations are made for actions likely to improve the condition of Griffin Creek and reduce its loading to impaired waterbodies downstream.
Start Date
1-4-2005 1:00 PM
End Date
1-4-2005 3:00 PM
Document Type
Poster
Watershed Assessment of Griffin Creek -- A major source of phosphorus to the Clark Fork River
Gold Creek has been identified as a major source of phosphorus to the nutrient-impaired Clark Fork River of western Montana. This watershed assessment is a follow-up to a study that found that the primary source of the phosphorus in Gold Creek was one of its tributaries, Griffin Creek. Selected aspects of Griffin Creek’s water quality, riparian and physical condition were studied to document current conditions and identify potential sources of impairment and restoration needs. Riparian assessments involved riparian vegetation and streambank stability surveys. The physical assessment documented substrate composition, channel morphology, in-stream temperature fluctuations, and stream discharge. Water quality assessments addressed nutrient and sediment levels and loads at two sites on Griffin Creek and seven other sites throughout the Gold Creek basin. The upper reaches of Griffin Creek were dominated by beaver ponds and showed healthy riparian vegetation and stable channel conditions. The lower three-fourths of Griffin Creek exhibited riparian and channel conditions damaged by grazing, flow manipulation, and beaver dam removal. Griffin Creek continues to be a major source of nutrients to Gold Creek and exhibits nutrient concentrations that exceed water quality standards set for the Upper Clark Fork River. However, Griffin Creek is unlikely to be impaired by nutrients since its fine substrate will not support massive algae growths. Recommendations are made for actions likely to improve the condition of Griffin Creek and reduce its loading to impaired waterbodies downstream.