Assessment - Southern Oregon Digital Archives

Population
The small, unincorporated town of Williams is located in the central portion of the
watershed, near the confluence of the East and West Forks of Williams Creek. Comprised
of a handful of businesses and public service facilities, Williams is the only established
settlement within the boundaries of the watershed. Residences are clustered on small
acreage plots in the Williams Valley and are scattered in larger holdings at higher
elevations.
In 1990, the U.S. Census Bureau estimated the population in Williams at 2,713 people.
This was an 8.8% increase from the 2,493 residents reported in the 1980 census (Preister
1994). Because the dominant land use zoning is commercial forestry, and because
Williams is a cul-de-sac valley, population growth is limited. Once a natural resource
dependent community, Williams now supports a growing number of people who work
elsewhere, are retired, or maintain small cottage industries.
Climate
The Williams Creek Watershed is part of the Western Lowlands climate zone. Partially
shielded from maritime influences by the Siskiyou Mountains, it experiences mild, moist
winters and warm, often hot, dry summers. Southwestern Oregon has the lowest average
summer precipitation and the highest average summer temperatures in the state. A Pacific
high-pressure center tends to dominate weather patterns in the summer months, during
which time only 5% of total precipitation occurs. Influxes of moist, tropical air are
sometimes diverted from their northerly migration, bringing occasional summer
thunderstorms to the Williams environs (Kimerling and Jackson 1985).
Precipitation occurs mainly in the winter months as a result of moist marine air blowing
in across the Pacific Ocean. Approximately one-half of the annual rain and snowfall
occurs during the November to January period, with almost all precipitation falling from
September to May. The highest precipitation takes place in December with an average of
6.72 inches. The driest month is July, which averages only 0.31 inches of rainfall.
Precipitation is heaviest in the higher reaches of the watershed and decreases at lower
elevations. Annual precipitation during the years from 1983 to 1998 averaged 33 inches
at a weather station on the valley floor (elevation 1,500 feet) and 51 inches in the Upper
Munger Creek drainage in the southwestern part of the watershed (elevation 2200 feet)
(Miles, L.Williams weather station analyst. Personal communication, Feb.1999).
Precipitation in the form of snow varies greatly according to elevation. Although there
are occasional accumulations of snow on the valley floor, areas below 2,200 feet do not
usually collect significant amounts of snowfall. Approximately 40% of the watershed is
in a Transient Snow Zone (TSZ), which falls in the middle elevations between 3,000 and
5,000 feet. Here, snow is frequent, but it is not retained as snow pack over the duration of
Williams Creek Watershed Assessment 9