Key Statistics

Location and Size

The Middle South Umpqua River-Dumont Creek fifth-field watershed is located in the southeastern portion of the Umpqua Basin. The watershed is 98,848 acres and includes 20 miles of the South Umpqua River from the community of Tiller upstream almost to South Umpqua Falls. The watershed stretches a maximum of 18 miles north to south and 15 miles east to west.

E&S Environmental Chemistry
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Landscape and Features

The Middle South Umpqua River-Dumont Creek Watershed has fairly consistent high relief topography. Elevations range from 5,520 feet at Quartz Mountain on the northeast tip of the watershed to 1,000 feet at Tiller at the base of the watershed. Other high-elevation areas include Cavitt Mountain (5,080') and Black Butte (5,051'). Streams within the watershed deeply dissect the landscape. River valleys broaden out in several places along the low end of the South Umpqua River and along Ash Creek in the northeast portion of the watershed.

Residents live primarily in the community of Tiller and in several of the broader tributary valleys throughout the watershed. There are no incorporated cities within the watershed. The only major roads within the watershed are the Tiller-Trail Highway (Douglas County Road #1), barely passing through the watershed's lower tip, and the South Umpqua Highway (Douglas County Road #46).

The most common land use in the watershed is forestry. Other uses include minor amounts of residential, agricultural, and commercial. Land ownership is primarily federal (87%), while private lands in the lower watershed make up nearly all the balance (13%). There are very small acreages of state and county ownership within the watershed.

Federal lands consist of those administered by the Umpqua National Forest and the Bureau of Land Management. These federal lands are roughly split into equal portions of late successional reserves and matrix lands. Late successional reserves are areas managed to protect and enhance conditions of late-successional and old-growth forest ecosystems. Matrix lands are those available for timber management at varying levels. The Tiller Ranger Station of the Umpqua National Forest is located within the watershed.

Current Conditions

Salmonids present in the Middle South Umpqua River-Dumont Creek Watershed are coho salmon, spring chinook salmon, winter steelhead, cutthroat trout, and rainbow trout. Other fish observed within the watershed are Pacific lamprey, western brook lamprey, speckled dace, Umpqua dace, Umpqua squawfish, Umpqua pikeminnow, sculpin species, redside shiner, and largescale sucker. Smallmouth bass have been observed in the South Umpqua River within the watershed, but are not thought to be year-around residents because of stream temperatures too low for the species.

As with many watersheds in southwestern Oregon, stream temperature limits water quality in much of the Middle South Umpqua River-Dumont Creek Watershed. The South Umpqua River and five of its tributaries are on the 2002 final ODEQ 303(d) list for summer stream temperature. South Umpqua River is also 303(d) listed for year around sediment and summer pH.

Many riparian areas within the watershed have been modified by timber harvest, salvage logging, road construction, hazard tree removal, and past stream clean out. These past practices have resulted in a shortage of in-stream large woody debris and riparian conifers for recruitment into the streams, thus creating less complex habitat. The 2002 Tiller Fire caused moderate to severe damage to 30 percent of the riparian areas within the watershed. This damage may result in a long-term shortage of large wood for in-stream structure, adversely affected streamflows, and fine sediment delivery to spawning and rearing habitat.

Aquatic habitat conditions in the watershed are marginal. Current fish habitat conditions in the tributary streams within the watershed vary from good to poor. High water temperature, low densities of large wood, and limited spawning gravel account for the less-than-ideal conditions. The South Umpqua River and many of its tributaries have been simplified into alternating areas of bedrock-dominated channel and deposition areas. Adequate levels of large woody debris do not exist to dampen high streamflows and trap bedload materials. Stream channels are constricted where roads are constructed within the flood plain.

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