The springs that issue forth on the east end of Reed canyon are the headwaters of Crystal Springs Creek, the purest water source in the Johnson Creek Watershed. The 21-acre canyon on the Reed College campus has historically provided habitat for a diverse array of wildlife. Between 1973 and 1993, four population inventories found 16 species of fish from eight different families in Reed Lake. These included: Chinook Salmon, Oncorhynchus tshawytscha (juveniles and adults); Steelhead and/or Rainbow trout, Oncorhynchus mykiss (juveniles and adults); Cutthroat Trout, Oncorhynchus clarki (juveniles and adults); Redside Shiner, Richardsonius balteatus (juveniles and adults); Speckled Dace, Rhinichthys osculus (adults); Largescale Sucker, Catostomus macrocheilus (juveniles and adults); Bridgelip Sucker, Catostomus columbianus (juveniles and adults); Brown Bullhead, Ameiurus nebulosus (adult); Threespine stickleback, Gasterosteus aculeatus; Pacific lamprey, Lampetra tridentata; and Prickly sculpin, Cottus asper (adults).
Bird inventories have documented 83 different types of birds that visit or breed at the site, including great blue heron, green-backed heron, orange-crowned warbler, yellow-rumped warbler, McGillivray's warbler and belted kingfisher. The canyon is home to one amphibian species, the terrestrial Oregon salamander (Ensatina eschscholtzii oregonensis). But the combination of lake, riparian and upland habitat could support other species as well, such as the rough skinned newt, western pond turtle, and tree frog. The location also provides habitat for beaver, muskrat, nutria, raccoon, squirrels, moles, shrews, rabbits, bats, marsupials, and oppossums. An assessment of fish and wildlife habitat commissioned by the Portland Parks and Recreation Department summarizes the value of the site for wildlife, noting that "the diversity of habitat types, plant diversity and quantity, and the mosaic of wetland communities make the Reed Canyon the highest quality habitat area within the City of Portland's portion of Johnson Creek basin."
But plant diversity has been gradually diminishing, replaced by invasive and noxious species. The site contains six plant species that have been listed as noxious weeds by the Oregon Department of Agriculture: Giant hogweed (Heracleum mantegazzianum), Canada thistle (Cirsium arvense), English ivy (Hedera helix), Himalayan blackberry (Rubus discolor), and Scotch broom (Cytisus scoparius). Native plants are also being suppressed by such invasives as English Holly (Ilex aquifolium), English Hawthorn (Crataegus laevigata), Western clematis (Clematis ligusticifolia), Traveler's Joy (Clematis vitalba), Bitter Nightshade (Solanum dulcamara), Field Bindweed (Convolvulus arvensis), and Reed Canarygrass (Phalaris arundinacea).
The impact of these noxious weeds and aggressive plants on the native plant communities in the Canyon and water quality is significant. By reducing, suppressing and replacing native and shade providing plants along stream corridors, English ivy ultimately increases erosion and sedimentation and reduces water quality necessary for aquatic wildlife. Ivy's streamside dominance results in more direct sunlight and higher water temperatures. This further degrades the water quality because warmer water has less capacity to carry oxygen. Finally, ivy's predominance in the landscape reduces food sources for terrestrial wildlife and the aquatic wildlife which feed on the organisms attracted by streamside and overhanging vegetation. Similarly, Himalayan blackberries create erosion on the banks of the canyon, pulling the bank down with its weight. Of the noxious weeds found at the site, the most extensive problems are being created by English ivy (Hedera helix) and Himalayan blackberry (Rubus discolor).
While the water quality of Reed Lake and Crystal Springs is good, other rivers, creeks and watersheds in Oregon have not fared so well. Habitat loss has contributed to the listing of eight species of salmon and steelhead in Washington and Oregon as threatened and one species as endangered by the National Marine Fisheries Service (NMFS) since 1998. The current listings affect the entire Willamette River watershed, both above the falls in Oregon City, including the Tualatin River and its tributaries, as well as below Willamette Falls to its confluence with the Columbia River.
Water quality and quantity are vital for salmon survival. Crystal Springs Creek is one of a handful of historic waterways in the Portland metropolitan area that has not been paved, rerouted, or drained. It flows for 2.1 miles past the Rhododendron Gardens and Crystal Springs Lake on the western edge of the Eastmoreland Golf Course and runs south through Westmoreland Park to Johnson Creek Park at the confluence with Johnson Creek, a tributary of the Willamette River. Crystal Springs benefits downstream water quality and quantity in several important ways: the constant nature of the flow dilutes suspended solids and sediment ; they help preserve Johnson Creek's flow in its lowest mile; and the naturally cool temperature of the flow may offset the negative impact of low summer flows in the watershed by providing a refuge for salmon).
Based on fish sampling data, the City of Portland has established a hypothesis that Johnson Creek, and its tributary, Crystal Springs, support an independent population of listed Columbia River steelhead trout. Portland's sampling work also demonstrates that fish from a number of streams south of Portland are using Crystal Springs during their migratory life cycles. Thus, the canyon project has the potential to provide improved habitat for all salmonids that use the Willamette River, not just the salmonids native to Johnson Creek and Crystal Springs.