Corvallis is the largest principal city of the Albany-Corvallis-Lebanon CSA, a Combined Statistical Area that includes the Corvallis metropolitan area (Benton County) and the Albany-Lebanon micropolitan area (Linn County), which had a combined population of 181,222 at the 2000 census.
As of the census of 2000, there were 49,322 people, 19,630 households, and 9,972 families residing in the city. The population density was 3,625.6 people per square mile (1,400.2/km²). There were 20,909 housing units at an average density of 1,537.0/sq mi (593.6/km²). The racial makeup of the city was 86.03% White, 1.16% Black or African American, 0.76% Native American, 6.42% Asian, 0.29% Pacific Islander, 2.52% from other races, and 2.82% from two or more races. 5.72% of the population were Hispanic or Latino of any race.
There were 19,630 households out of which 24.0% had children under the age of 18 living with them, 40.8% were married couples living together, 7.2% had a female householder with no husband present, and 49.2% were non-families. 31.5% of all households were made up of individuals and 7.5% had someone living alone who was 65 years of age or older. The average household size was 2.26 and the average family size was 2.88.
In the city the population was spread out with 17.7% under the age of 18, 28.4% from 18 to 24, 27.0% from 25 to 44, 16.8% from 45 to 64, and 10.1% who were 65 years of age or older. The median age was 27 years. For every 100 females there were 99.2 males. For every 100 females age 18 and over, there were 98.2 males.
The median income for a household in the city was $35,236, and the median income for a family was $53,208. Males had a median income of $40,770 versus $29,390 for females. The per capita income for the city was $19,317. About 9.7% of families and 20.6% of the population were below the poverty line, including 15.2% of those under age 18 and 6.0% of those age 65 or over.
According to the federal Environmental Protection Agency report on its “green power communities,” Corvallis buys more power from renewable resources than any other city in the nation. Corvallis purchases more than 100 million kilowatt-hours of green power annually, which amounts to 13 percent of the city’s total purchased electricity.
Long-distance bus service is provided by both Amtrak and Greyhound. They both stop at the Greyhound station in downtown Corvallis (station ID: CVI.)
Local bus service is provided by Corvallis Transit System (CTS). The system runs a total of eight daytime routes Monday through Saturday, covering most of the city and converging at a Downtown Transit Center. Additional commuter routes also run in the early morning and late afternoon on weekdays, and mid-morning and mid-afternoon on Saturdays. When Oregon State University is in session CTS also runs the "Beaver Bus," a set of late-night routes running Thursday through Saturday.
Two other short-distance inter-city buses — the Linn-Benton Loop (to Albany), and the Philomath Connection, also stop at the Downtown Transit Center.
Designated a "Bike-Friendly City," Corvallis has many miles of bike paths, trails, and roadside bicycle lanes. The bulk of the city is also very flat lending itself even moreso to sight-seeing cycling. Many miles of mountain bike trails, ranging from easy to very technical, abound in the outskirts of the city, with the highest concentration present in the Oregon State University research forest (MacDonald and Dunn forests).
The city's water system contains two water treatment plants, nine processed water reservoirs, one raw water reservoir, and some 210 miles (340 km) of pipe. The system can process up to about 19 million gallons of water per day.
The Rock Creek treatment plant processes water from sources in the 10,000-acre (40 km) Rock Creek Municipal Watershed near Marys Peak. The three sources are surface streams which are all tributaries of the Marys River. Rock Creek has a processing capacity of 7 million gallons of water per day (gpd), though operational characteristics of the 9-mile (14 km), 20-inch (51 cm) pipeline to the city limits capacity to half that. The Rock Creek Plant output remains steady year round at about 3 million gpd.
The H.D. Taylor treatment plant obtains water from the Willamette River, and has been expanded at least four times since it was first constructed in 1949. Its output varies seasonally according to demand, producing from 2 to 16 million gallons per day, though it has a capacity of 21 million gpd.
The total reservoir capacity is 21 million gallons, though measures to voluntarily reduce water usage begin when reservoir levels fall below 90% of capacity, and become mandatory at 80% or below. As part of its ongoing water conservation program, the water department jointly publishes a guide to water-efficient garden plants.