Coquille Subbasin Working Atlas - p2
The Coquille Subbasin
Page 2: The Coquille Subbasin
Page 6: Vegetation and Land Cover
Page 8: Water Use and Availability
Page 9: Fish Distribution & Habitat
The 1,032 square mile Coquille Subbasin includes five subdivisions based on the primary tributaries of the Coquille River — the North Fork; East Fork; Middle Fork; and South Fork — and the main-stem of the Coquille below the confluence of the North and South Forks. As indicated in Table 1, there are 3,280 miles of stream within the Coquille Subbasin, as identified from 1:100,000 scale USGS maps. There are an average of 3.8 stream miles per square mile of land area in the subbasin. Average drainage density by subdivision ranges from a high of 4.5 in the Coquille subdivision to a low of 3.5 in the South Fork of the Coquille.
Stream data used in this analysis and in most of the atlas are from the Pacific Northwest River Reach File. This data was developed by the EPA from 1:100,000 scale USGS maps. This data is currently the largest scale stream data that is consistent and accurate throughout the entire subbasin.
Road data used in most of the atlas are from the Bureau of the Census 1:100,000 scale Census Tiger data. This is the largest scale road data that provides complete and consistent coverage throughout the entire subbasin. Many smaller forest roads are not shown in this data. There are approximately 2,389 miles of road in the Coquille subbasin, based on the 1:100,000 scale data. As indicated by Table 2, the density of roads (miles of road per square mile of land area) is highest on private non-industrial land. This is not surprising since the towns and residential areas fall into this ownership category. As a group, private industrial land ownerships appear to support the lowest road density
Key watersheds
| Table 2: Stream Drainage Density by Subdivision | |||
| Subdivision | Area (sq. mi.) | Stream Miles | Drainage Density (mi./sq. mi.) |
| Coquille | 170 | 771 | 4.5 |
| North Fork Coquille | 155 | 668 | 4.3 |
| East Fork Coquille | 133 | 518 | 3.9 |
| Middle Fork Coquille | 302 | 1,136 | 3.8 |
| South Fork Coquille | 272 | 958 | 3.5 |
| Totals | 1,032 | 3,280 | 3.8 |
Key watersheds (shown in Key Watersheds and NPDES Discharge Sites and Permanent Stream Gages) were delineated by the Forest Ecosystem Management Assessment Team (FEMAT) in 1993. Defined by Forest Service and Bureau of Land Management fish biologists, they include watersheds that (1) are greater than 6 square miles with high-quality water and fish habitat, and (2) contain habitat for potentially threatened species or stocks of anadromous salmonids or other potentially threatened fish.
Adopted as part of an aquatic conservation strategy under the President's Forest Plan, key watersheds are primarily designed as refugia critical to at-risk stocks of anadromous salmonids and resident fish species. Key watersheds either provide or are expected to provide high quality habitat. They include areas of high quality habitat as well as areas of degraded habitat with high potential for restoration. Tier 1 watersheds were selected for directly contributing to anadromous salmonid and bull trout conservation. Tier 2 key watersheds were selected as sources of high quality water and may not contain at-risk fish stocks. The three key watersheds within the Coquille subbasin — the Upper North Coquille, Cherry Creek, and the South Fork Coquille — are all Tier 1 watersheds.
Under the Standards and Guidelines for Management of Habitat for Late-Successional and Old-Growth Forest Related Species Within the Range of the Northern Spotted Owl (1994), most resource management activity on federal lands within key watersheds — including timber harvest and salvage — was suspended pending the completion of watershed analyses. Key watersheds have the highest priority for watershed restoration within the area of the President's Forest Plan. A primary objective of the aquatic conservation strategy within key watersheds is to prohibit the construction of new roads in existing roadless areas and reduce the extent of the existing road network.
| Table 3: Road Density by Ownership Class | |||
| Owner Class* | Area (sq mi) | Road Length (miles) | Road Density (mi / sq mi) |
| PNI | 303 | 892 | 2.9 |
| PI | 373 | 651 | 1.7 |
| BLM | 239 | 548 | 2.3 |
| USFS | 100 | 255 | 2.6 |
| other | 16 | 44 | 2.7 |
Discharge sites
Permitted point source discharge sites are also shown in Key Watersheds and NPDES Discharge Sites and Permanent Stream Gages. There are 21 permitted National Pollution Discharge Elimination Sites (NPDES) in the Coquille Basin. Sixteen of those sites are industrial, four are domestic and one is agricultural. Most of these sites are located along the Coquille between the cities of Coquille and Myrtle Point.
