The following summary is based on data from the 2023 Watershed Health Index. The scores below are a snapshot of conditions across the entire watershed. Conditions can vary in smaller parts of the watershed.
The scores from 2019 and 2015, the first year Environmental Services released the report cards, are included.
Water Quality Score: B
Tryon Creek contains valuable aquatic habitat, but because of water quality issues the health of the watershed is low. E. coli bacteria levels often exceed state water quality standards. Untreated stormwater sends sediment and pollutants into the stream. Projects to repair and replace old sewer and stormwater pipes help improve water quality.
Scores for Water Quality Indicators
Scores are on a scale of 0 to 10 with scores of 8 or higher meaning the indicator is properly functioning. A score of 3 or lower means the indicator is not functioning properly or provides little to no support for a healthy watershed. Find more information about the indicators and how to read the scores.
| Water Quality Indicator | 2023 Score | 2019 Score | 2015 Score |
|---|---|---|---|
| Ammonia-Nitrogen | 9.9 | 9.9 | 9.9 |
| Dissolved Copper | 6.0 | 5.9 | 5.7 |
| Dissolved Oxygen | 8.7 | 8.6 | 8.6 |
| E. coli | 4.3 | 2.9 | 5.3 |
| Temperature | 4.1 | 4.9 | 5.0 |
| Total Mercury | 4.1 | 1.8 | 1.8 |
| Total Phosphorus | 6.3 | 6.3 | 6.6 |
| Total Suspended Solids | 5.9 | 3.8 | 5.7 |
Habitat Score: B+
Habitat conditions are different throughout the watershed. The best habitat conditions exist in the Tryon Creek State Natural Area. There is room for improvement both above and below this area. Stream accessibility is a challenge, as culverts create barriers for fish passage. The recent SW Boones Ferry Bridge and Stream Restoration project replaced a culvert with a bridge which will help fish reach habitat in the upper portions of Tryon Creek.
Scores for Habitat Indicators
Scores are on a scale of 0 to 10 with scores of 8 or higher meaning the indicator is properly functioning. A score of 3 or lower means the indicator is not functioning properly or provides little to no support for a healthy watershed. Find more information about the indicators and how to read the scores.
| Habitat Indicator | 2023 Score | 2019 Score | 2015 Score |
|---|---|---|---|
| Bank Condition | 10.0 | 9.8 | 10.0 |
| Floodplain Condition | 9.8 | 10.0 | 10.0 |
| Large Wood | 5.0 | 7.4 | 4.8 |
| Riparian Integrity | 6.9 | 7.2 | 6.9 |
| Shallow Water Refugia | Not applicable | Not applicable | Not applicable |
| Stream Accessibility | 1.9 | 1.9 | 1.5 |
| Substrate Composition | 7.9 | 6.0 | 2.3 |
| Tree Canopy | 10.0 | 10.0 | 10.0 |
Hydrology Score: B
Roads, roofs, and parking lots impact streams in the Tryon Creek watershed. These impervious surfaces create “flashy” hydrology during storm events. Heavy rains lead to stream bank instability and sediment deposits in stream beds. We are improving hydrologic conditions with projects like the Basin 3/Tryon Headwaters to better manage stormwater.
Scores for Hydrology Indicators
Scores are on a scale of 0 to 10 with scores of 8 or higher meaning the indicator is properly functioning. A score of 3 or lower means the indicator is not functioning properly or provides little to no support for a healthy watershed. Find more information about the indicators and how to read the scores.
| Hydrology Indicator | 2023 Score | 2019 Score | 2015 Score |
|---|---|---|---|
| Effective Impervious Area | 5.7 | 5.3 | 5.2 |
| Stream Connectivity | 6.7 | 6.8 | 6.8 |
Fish and Wildlife Score: D
Cutthroat trout and reticulate culpin are the most abundant fish detected during stream surveys. Coho and chinook salmon, steelhead, and other native fish are also present in Tryon Creek. A culvert at Highway 43 significantly blocks fish from swimming up Tryon Creek to the prime habitat in the Tryon Creek State Natural Area. Environmental Services is working on a project to remove the culvert, which will open up the entire creek to fish.
Scores for Fish and Wildlife Indicators
Scores are on a scale of 0 to 10 with scores of 8 or higher meaning the indicator is properly functioning. A score of 3 or lower means the indicator is not functioning properly or provides little to no support for a healthy watershed. Find more information about the indicators and how to read the scores.
| Fish and Wildlife Indicator | 2023 Score | 2019 Score | 2015 Score |
|---|---|---|---|
| Birds | 5.9 | 4.1 | 4.7 |
| Fish | 0.6 | 2.1 | 2.0 |
| Macroinvertebrates | 3.2 | 5.0 | 5.7 |
In Summary
The above-average scores for most of the Tryon Creek watershed demonstrate the impact of our work. Decades of projects to manage and treat stormwater have improved water quality, hydrology, and habitat. We are hopeful that upcoming projects will further improve water quality as well as fish and wildlife scores.
Read more about the Tryon Creek watershed.