Percival Creek

Local Streams

In the hustle and bustle of today’s lifestyle, this little gem of a creek is often overlooked as it flows through the urban areas of both Tumwater and Olympia. Many local residents are unaware of Percival Creek’s nearby presence as they shop at Costco, visit the Capitol Auto Mall or do business at the Thurston County Courthouse.

Percival Creek: Urban Treasure

The headwaters of Percival Creek are located at Trosper Lake in Tumwater. From there, it flows north through Tumwater and the campus of South Puget Sound Community College and meets up with Black Lake Ditch. The creek then parallels and crosses Highway 101 in Olympia and flows through Percival Creek Canyon, along the base of the Courthouse Hill area to Percival Cove off of Capitol Lake.

In the hustle and bustle of today’s lifestyle, this little gem of a creek is often overlooked as it flows through the urban areas of both Tumwater and Olympia. Many local residents are unaware of Percival Creek’s nearby presence as they shop at Costco, visit the Capitol Auto Mall or do business at the Thurston County Courthouse.

The Percival Creek watershed covers 4,712 acres. It flows for 5.6 miles, 5.5 miles of which are available habitat for anadromous species. Species which use the creek include Chinook, coho, chum and cutthroat trout. In addition, bull trout are found in the nearshore area near the mouth of the creek.

Local Streams

Percival Creek bears the name of a prominent pioneer sea captain, Captain Sam Percival, who owned a saw mill at the mouth of Percival Creek. The Percival basin was logged, and the logs were processed at the sawmill. After logging, rail tracks on an earthen berm were built across the mouth of Percival Creek, creating Percival Cove on the southwest side of Budd Inlet.

Before pioneers, like Sam Percival, brought changes to the landscape, the Squaxin Island Tribe harvested shellfish from lower Budd Inlet near the mouths of Percival Creek and the Deschutes River. Back then, the journey of Percival Creek was less complicated, and Percival Creek flowed from Trosper Lake more directly to Puget Sound, via Budd Inlet.

A major change occurred to the watershed in 1922: the digging of Black Lake Ditch from the north end of Black Lake to Percival Creek. Black Lake originally flowed only to the south into the Black River and the Chehalis Watershed, terminating at Grays Harbor. The ditch at the north end of the lake now connects Black Lake to the Percival/Deschutes Watershed in the opposite direction, terminating at Puget Sound’s Budd Inlet. Black Lake now is part of two watersheds; it’s an unusual, and unnatural, occurrence!

The second major change was the creation of Capitol Lake in 1951. This man-made, freshwater lake replaced the estuary of lower Budd Inlet. This created quite a change for the mouth of Percival Creek. Where it once flowed into a saltwater estuary, it now flows into fresh water, and the transitional estuary area disappeared. This had an impact on salmon and other fish and wildlife populations in Percival Creek ecosystem. Deschutes Parkway now crosses the mouth of Percival Creek. Sediment transport has been impacted, gradually turning the mouth of Percival Creek at Percival Cove into a shallow basin.

Another change to Percival Creek came from the installation of a “gate” by Washington Department Fish and Wildlife (WDFW), on the lake side of the bridge by Marathon Park. The gate is in place during the fall and encourages the hatchery run of Chinook up into the Deschutes, so that the fish can be harvested for their eggs and milt. This in turn, also encourages other species, including some native Percival coho, up the Deschutes. WDFW opens the gate in mid-October after they have harvested enough eggs and milt for the season.

Up until 2007, Percival Cove was used by WDFW to rear yearling Chinook salmon, as well as to imprint the Deschutes system in hatchery fish reared elsewhere. Due to large numbers of fish and their food pellets, as well as the cumulative effects of impacts from the whole watershed, WDFW could no longer meet Department of Ecology water quality standards for nitrates and sediment loads. Thus, the Percival Cove rearing site was abandoned after the 2007 rearing season. Juvenile Chinook are now reared in the holding ponds at Tumwater Falls Park. The gate at Percival Cove is planned to be eventually removed by WDFW.

The first major urban development of the modern era in the Percival Basin was the Ken Lake development in the 1960s. Many other residential developments have followed, and, today, more than 50% of the basin area is urbanized. This urbanization has increased stormwater flows and its negative impacts on water quality in Percival Creek.

Local governments began making improvements to the creek and its riparian buffer in the 1990s, including the replacement of a fish-blocking culvert at Chapparel Drive by City of Tumwater. The City of Olympia replaced a culvert at Mottman Road on Black Lake Ditch, created a constructed wetland stormwater treatment area at Black Lake Meadows and installed two fish ladders on lower Percival Creek.

Percival Creek, at South Puget Sound Community College, is one of the original benthic macroinvertebrate monitoring sites for Stream Team. Tumwater Middle School students perform chemical monitoring at four sites along the creek in Tumwater and previously monitored a site in Olympia in Percival Canyon. Thurston County performs ambient monitoring at the mouth of Percival Creek.

In the past twenty years, macroinvertebrate samples collected by Stream Team volunteers have shown Percival Creek to be of “moderate biologic integrity” for aquatic life. Student volunteers have found acceptable pH levels and mostly adequate to good levels of dissolved oxygen and nitrates; high temperatures, high turbidity and fecal coliform have occasionally been found. In 1995, student monitors found an alarmingly high level of fecal coliform in Percival Canyon. This information lead government staff to the discovery and repair of a leaking sewer line in the canyon.

Stream Team volunteers have been very active in the Percival Creek watershed. Habitat enhancement projects on both sides of Black Lake Ditch have been undertaken by Thurston County and Olympia Stream Teams. Reed canary grass was so thick that the channel was in danger of being completely choked out by this invasive species of grass. Willow and red-osier dogwood stakes were planted along the banks, and native trees were planted in the upland area. The sites, especially Black Lake Meadows, needed additional plant protection due to the presence of beaver.

A twelve-acre property north of Sapp Rd. along Percival Creek has been the site of an on-going Tumwater Stream Team habitat enhancement project. Hundreds of volunteer hours have been logged at this site. The property was deeded to the Sapp family by President Ulysses S. Grant and served as a dairy for early Tumwater. The land was subsequently used to graze beef cattle and horses. Upon the development of Streamland Estates, the riparian piece of property became the property of Tumwater Parks and Recreation. It is slated to become an urban wildlife-viewing park.

The livestock-related land use had a heavy impact on the riparian corridor along this portion of the creek. Most of the native trees and shrubs had been removed. Reed canary grass was planted to feed the livestock. Over time, the soil became compacted and the removal of native vegetation caused temperatures and sediment loads to increase and exacerbated damage from flood/drought events. The native salmon almost disappeared from the stream.

Over the past ten years, Stream Team volunteers have planted and maintained over 10,000 native trees and shrubs on the property. The site is now home to deer, many species of birds and other wildlife. Two years ago, three Chinook salmon made it to the Sapp Road site to spawn. Unfortunately, they were all male, but at least salmon are returning!