Fish Creek winds roughly 15 miles from Teton Village to its confluence with the Snake River. A groundwater-fed spawning stream for the Snake River fine-spotted cutthroat trout, it has drawn anglers since the late 1800s and provides crucial riparian habitat on the west bank of the Snake River. Because it flows predominantly through private land, its future largely depends on the stewardship of the people who live alongside it. Research beginning in 2004 has determined that algae growth in Fish Creek was higher than in comparable streams and that nutrients entering the creek from nearby land uses were problematic, including agriculture, wastewater treatment plants and septic systems, and fertilizers. In 2020, the entire length of Fish Creek was listed as impaired for E. coli bacteria. In 2025, WDEQ added an additional impairment for nutrients (excess nitrogen and phosphorus) along the upper 9.6 miles between Teton Village and Wilson. The Fish Creek Watershed Plan outlines 38 best management practices aimed at improving water quality in Fish Creek. It has been approved by WDEQ as a nine-element watershed-based plan and an Advance Restoration Plan, qualifying Fish Creek projects for crucial Clean Water Act funding.

Flat Creek has been designated as an impaired stream by the Wyoming Department of Environmental Quality since 1996. In response to that listing, which identifies stormwater runoff and habitat alteration as root problems, the Flat Creek Watershed Management Plan was drafted in 2006. This stakeholder- and community-driven effort established a baseline understanding of the issues facing Flat Creek and identified a series of actionable projects to address those challenges. Since 2006, twenty of the twenty-two objectives outlined in the Watershed Plan were completed, making the original plan outdated. With a grant from the Wyoming Department of Environmental Quality, Teton Conservation District led an effort to bring the Flat Creek Watershed Management Plan up to date. The revised plan includes new project ideas, a list of accomplishments, summarizes existing data, and sets discrete goals for water quality and stream health in Flat Creek.