The Creeks Beneath the Fields

This article is the first of a five part journalism series by the San Juan Islands Conservation District on streams and wetlands in the islands, and what people can do to restore them.

On summer mornings in the San Juan Islands, the freshwater world can feel almost imaginary. Streams are often hidden behind pastures or culverts, wetlands tucked into folds of land that most people drive past without noticing. The islands appear governed by stone, saltwater light, Garry oak, and wind-bent fir. Yet, before roads, fences, and drainage ditches reorganized the archipelago, freshwater shaped nearly every inhabited valley in the islands.

At the headwaters of Crow Valley Creek on Orcas Island, cold water still moves through alder thickets and skunk cabbage wetlands before slipping beneath open pastures. Along parts of Garrison Creek on San Juan Island, remnant willow and cottonwood stands survive where floodwaters once spread seasonally into wet meadows now fragmented by roads and development. Near False Bay, pockets of sedge marsh still hold moisture deep into August, while on Shaw Island small springs emerge quietly beneath sword fern slopes before disappearing into modified drainage channels.

Each of these are fragments of freshwater systems that were once far more connected than they appear today.

Historical accounts repeatedly describe wetter valley bottoms than many island residents would recognize now. In nineteenth-century survey notes compiled by the U.S. Coast and Geodetic Survey, portions of San Juan Valley and Eastsound Flats were described as seasonally saturated and difficult to traverse during winter months. Early agricultural histories later celebrated the draining of these “swamp lands” into productive pasture and hay fields.

The transformation unfolded faster than memory but slower than geology.

Between the late nineteenth century and the middle of the twentieth, wetlands throughout Puget Sound were systematically diked, drained, filled, or converted to agriculture. In the Puget Sound River History Project: River and Wetland Loss Studies (2005), the Puget Sound Nearshore Ecosystem Restoration Project estimated that major estuarine systems in Puget Sound have lost roughly seventy percent of their historical tidal wetlands since Euro-American settlement. The San Juan Islands escaped the industrial-scale river engineering seen in places like the Skagit Delta, but the archipelago experienced its own quieter hydrologic simplification through ditching, grazing, clearing, and shoreline alteration.

Coast Salish histories describe these landscapes very differently.

In The Earth’s Blanket: Traditional Teachings for Sustainable Living (2005), Nancy Turner documents how Coast Salish communities throughout the Salish Sea actively managed wet prairies, estuaries, and valley bottoms through cultural burning, selective harvesting, and long-term stewardship. Species such as camas, springbank clover, nettles, crabapple, and wapato were not simply gathered opportunistically; many landscapes were intentionally maintained to support them.

Wet prairies near modern-day American Camp and seasonal wetlands around Zylstra Lake likely functioned as complex cultural landscapes shaped by generations of stewardship. River bottoms and estuarine edges provided materials for basketry, medicines, and access to salmon runs moving inland from the Salish Sea.

In many places, what settlers later interpreted as naturally open prairie or pasture had, in fact, been actively maintained for centuries.

Modern ecological research increasingly supports these oral histories. In Keeping It Living: Traditions of Plant Use and Cultivation on the Northwest Coast of North America (Deur & Turner, 2005), researchers describe how Indigenous burning practices likely shaped portions of the Garry oak and wet prairie ecosystems that settlers later interpreted as “natural openings.”

Then the hydrology changed.

Beginning in the late nineteenth century, settlers systematically drained wetlands throughout the islands to create agricultural land. Creeks were straightened into ditches. Beaver wetlands were eliminated. Forested riparian corridors were cleared to maximize grazing acreage and reduce shade over hay fields. Seasonal wetlands near agricultural flats were converted into increasingly efficient drainage systems. Across the archipelago, freshwater was re-engineered to leave the land as quickly as possible.

The changes often seemed practical and incremental. A ditch hand-dug beside a pasture. A tide gate installed near an estuary. A small pond excavated to water livestock. But cumulatively, these decisions reshaped the islands’ ecological memory.

What restoration practitioners increasingly recognize is that the islands’ freshwater systems were never separate from forests, salmon, agriculture, or people. They functioned as interconnected living infrastructure.

Scientists now use that phrase quite literally. According to the U.S. Natural Resource Conservation Service, wetlands reduce downstream flooding, improve water quality by filtering nutrients and sediment, recharge groundwater, and store disproportionately large amounts of carbon relative to their size. A mature riparian forest can reduce summer stream temperatures dramatically through shade alone, while floodplains slow winter runoff and increase infiltration into groundwater systems.

For islands existing within the rainshadow of the Olympic Mountains, these functions matter enormously.

And in scattered corners of the archipelago, they still persist quietly: a cedar-lined seep above Olga, a wet meadow beneath Turtleback Mountain, a willow filled tributary feeding False Bay Creek after autumn rain.

To learn more please visit https://www.sanjuanislandscd.org/streamsandwetlands