Coffelt Farm Preserve

While developing the 2020 Coffelt Farm Preserve Stewardship and Management Plan the Land Bank identified an opportunity to protect and enhance the small, perennial stream that flows from south to north across the preserve. The stream had field fencing along its west side but was accessible to farm animals from the east. It was bordered by small alders, willows, Douglas spiraea and swamp rose as well as Himalayan blackberry and a large expanse of invasive reed canary grass. In open areas, the latter hinders the establishment of native trees and shrubs by suppressing germination and by harboring meadow voles, which girdle young seedlings.

The stream channel was likely excavated from wetlands in the late 1800’s and carries perennial flow from spring sources in the southeast corner of the Preserve northward to Fowler’s Pond Preserve and Judd Cove. A smaller, partially ditched stream conveys seasonal flow from Turtleback Mountain eastward across the wetland to the main channel. Historically, both channels were dredged periodically to promote drainage. These activities altered the extensive wetlands that once covered much of the area. The introduction and subsequent expansion of reed canary grass also changed the wetlands. Despite these changes, a 2022 botanical survey by the Land Bank identified at least 25 native wetlands species.

Since 2020, the Land Bank has planted approximately 5,000 trees and shrubs. These plants will help suppress reed canary grass in the channel by increasing shade. Along with new fencing along the east side of the channel to exclude farm animals, an enhanced riparian forest buffer will provide habitat for native species and help protect water quality. It may also improve channel conveyance capacity over time by reducing reed canary grass cover, which is known to reduce flow velocity and to promote sediment deposition in low-gradient stream channels. Although anadromous fish cannot access the stream due to a waterfall near the mouth, increased riparian cover will also help to maintain cool water temperatures and improve habitat for other aquatic species.

There is anecdotal evidence that the small population of beaver on Orcas Island may be increasing. Beaver have long been an integral part of the local ecology and provide many benefits. They can also have severe impacts on narrow riparian buffers and can exacerbate local flooding. The Land Bank will continue to review best management practices for maintaining the ecological health of this small stream while also recognizing the agricultural benefits provided by Coffelt Farm Preserve.

For more information regarding this project, please contact Preserve Steward, Peter Guillozet at 360-289-0052 or at peterg@sjclandbank.org.