The Johnson Creek Watershed—An Oasis in the Urban Jungle

The Johnson Creek Watershed—An Oasis in the Urban Jungle

Kevin Douglas Hay

The Johnson Creek Watershed is a unique and biologically diverse ecosystem within an ever-growing anthropomorphic infrastructure. From feeding indigenous people, to supplying the power to mill grain, to providing public parks and wild refuges, the Johnson Creek Watershed is a cultural and natural treasure. Pre-Portlanders settled in the drainage basin drawn by its beauty and abundant natural resources. By the early 20th century, a railway line, various types of industry, agriculture, and homes filled the Watershed, dependent upon its clear cool water to power machines, irrigate fields, provide food and recreation, and to wash away the unwanted and unneeded refuse and residue of the industrial world.

Today, the Johnson Creek Watershed presents many challenges and opportunities. Environmental Scientists, Engineers, Urban Planners and students are all over the world are attracted to the Watershed, they come to see how population and economic growth can not only coincide with nature, but how nature itself can be a primary consideration when planning urban growth. But what is the Johnson Creek Watershed and how does it interact with the infrastructure of the Portland Metropolitan Area? What are the current environmental issues impacting the Watershed’s ecosystem? Who is responsible for restoration efforts and what is being done to repair this unique ecosystem?

The Johnson Creek Watershed encompasses 140 square kilometers of residential, rural, and commercial / industrial Clackamas and Multnomah Counties and is part of the Lower Willamette Basin which is a sub-basin of the Columbia River Drainage Basin. The Johnson Creek Watershed consists of a number of smaller sub-watersheds. Kelly Creek, Mitchell Creek, Veterans Creek, Butler Creek, Sunshine Creek, Badger Creek, Crystal Springs, Errol Springs Creek and others all flow into Johnson Creek. (Named for William Johnson, who built a saw-mill on the creek in 1846)  The elevation varies from the headwaters of Johnson Creek at 335m near the town of Cottrell Oregon, down to 8m at the confluence of the Willamette River. The Watershed is confined by Gresham Butte, Jenne Butte, and Mt Scott to the south, and Hogan Butte, Powell Butte, Kelly Butte, Rocky Butte and Mt. Tabor to the north. The Johnson Creek Watershed basin formed between 13,000 and 15,000 years ago during the Missoula Floods events. Johnson Creek itself is one of the last of Portland’s free flowing creeks.

The Johnson Creek Watershed boundary includes parts of 2 counties, 4 cities, and a large section of unincorporated areas. Thirty-eight percent of the Watershed is within Portland city limits, 23 percent within the city of Gresham, 4 percent of Milwaukie, 0.1 percent of Happy Valley. The remaining 33 percent of the Watershed lies within unincorporated Multnomah and Clackamas counties2. Sixty percent of the water in the Johnson Creek Watershed system comes from surface run-off.  In 2000, the Johnson Creek Watershed drained surface water from 53 percent of Gresham, 42 percent of Milwaukie, 19 percent of Happy Valley, and 14 percent of Portland. Of the 140 square kilometers which make up the Watershed, 54 percent is residential, 33 percent is rural, 8 percent is commercial/industrial and 5 percent is parks and open space, 70 percent of The Johnson Creek Watershed is within the Urban Growth Boundary. In 2006, there were 175,000 people living within the boundaries of the Johnson Creek Watershed. But human beings are not the only inhabitants of the Watershed.

Salmon runs on Johnson Creek and its tributaries once fed indigenous people and early European settlers. There is anecdotal evidence of fall salmon runs being so thick that you could walk across the creek on their backs or catch them with a pitchfork. An Oregon Fish and Wildlife fish inventory conducted in 2001-2002, documented 17 Chinook salmon, and 5 Coho salmon. Other salmonid species counted at the time were 101 cutthroat trout and 1 steelhead trout. In December of 2010, 3 Coho salmon carcasses were spotted in Johnson Creek near the city of Gresham, the Oregon Department of Fish and Wildlife is currently conducting a spawning survey of Coho salmon through-out the Watershed.  As of the writing of this paper 1 live Coho salmon and 3 Coho salmon carcasses had been spotted near the eastern border of Gresham.

A number of “sensitive” species, created under Oregon’s Sensitive Species Rule (OAR 635-100-040) also inhabit the watershed.  Red-legged frogs, painted turtles, long-toed, northwestern, and Columbia salamander are just a few examples.

Mammals such as river otter, beaver, nutria, raccoons, and possum are common along the 46km stretch of the Watershed. Larger mammals such as black tailed deer and coyotes can still be seen on occasion, while sightings of elk, black bear, cougar or bobcat are few and far between. Birds are by far the most common form of wildlife in the watershed. Ducks, herons, geese, owls, hawks and a number of other birds make their homes among the diverse microclimates of the watershed.

Flora along the Watershed was much the same as the rest of the Lower Willamette Basin prior to European settlement. Douglas-Fir, Western Red Cedar, Ash and Alder forests once dominated the area, most of which have succumb to urban/suburban sprawl. Invasive species such as Himalayan Blackberry, English Ivy, and Wild Clematis have now become problematic especially along riparian corridors. Massive declines in fish populations and the invasion of non-native plant species has not been the result of natural causes. The degradation of native flora and fauna and contamination of the aquatic ecosystem began almost immediately after the first European settlers colonized the Watershed.

As a result of human activity throughout the watershed for the past 150 years, water quality within the Johnson Creek Watershed has been deemed hazardous for consumption and recreation. The use of pesticides and herbicides in agricultural areas has created a long lasting legacy effect on soil components, industries such as the milling and treatment of lumber, metal plating, and chemical manufacturing have leeched toxic elements into the soil and water column, and deforestation has increased erosion and raised the water temperature through-out the Watershed.

DDT (dichlorodiphenyltrichloroethaneand) Dieldrin were banned in the U.S. in 1972, thanks in part to the publication of Rachel Carson’s Silent Spring. DDT and Dieldrin are considered legacy pesticides because they remain in the soil and are not easily broken down through natural processes. In 1988 the USGS documented high levels of these pesticides in the streambeds of the Johnson Creek Watershed. These compounds typically remain bound to soil particles, however; they are released whenever soil or sediment is disturbed and wash into the Watershed after large rain events. A 2003-2004 study suggests that there is a strong correlation between elevated levels DDT and Dieldrin and soil suspended in water after rain storms. Furthermore; samples collected in urban and rural areas exceeded acceptable water quality standards.

The Oregon Department of Environmental Quality has classified Johnson Creek a “waterbody of concern” due to high concentrations of metals such as copper, nickel and chromium. According to the DEQ’s water quality index, (10 being worst and 100 being ideal) Johnson Creek was rated a 26. (The Willamette River at the Hawthorne Bridge was rated 74 during the same period.)

Compounding the impact on aquatic organisms is water temperature. Mean water temperature for June, July and August recorded in 2010 was 14.6, 18.7, 18.6 degrees Celsius, with average maximums of 21.1, 24.8, 23.5 degrees Celsius. Adult Coho salmon can survive for short periods in water at 24 degrees Celsius, successful salmon rearing occurs in water with an average temperature of 17.8 degrees Celsius.

In order to make room for agriculture, industry, and homes, vast numbers of trees were cut down, waterways were straightened and channelized, culverts narrowed stream channels, and wetlands were drained. As a result, the frequency and magnitude of flooding has increased dramatically through-out much of the Watershed.

Prior to the 20th century, it was estimated that there were more than 30 creeks and streams that fed into the Watershed, most of which have filled-in, obstructed, or paved over and diverted into the storm water systems of Gresham, Portland, and Milwaukie.  During the 1930’s and 1940’s, under President Franklin D. Roosevelt’s ‘New Deal’, the Works Progress Administration completed projects along 24 kilometers of Johnson Creek. These projects were meant to control flooding and stream-bank erosion. Unfortunately, these projects accomplished very little other than putting unemployed Americans back to work, and increase flooding through-out the Watershed. Due to the many manmade alterations to the Watershed, Johnson Creek floods every other year on average. Johnson Creek has exceeded flood stage 39 times from 1941 to 2008 and between 1978 and 1997 the Federal Emergency Management Agency estimates that 156 flood insurance claim totaling $2,015,300 had been paid.  In 1996 the USGS recorded the highest flood waters on record for Johnson Creek, 1.2 meters above flood stage. (3.4 meters) Flooding of the Watershed not only impacts the human infrastructure by causing damage to property and utilities, regular flooding also has the potential to introduce toxins from the soil of the upper rural Watershed into densely populated areas of the lower Watershed.

For many years jurisdiction of the Johnson Creek Watershed had been administered by a bevy of local municipalities and state agencies. Cohesive policies and actions governing the Watershed were difficult to achieve due to the diversity of communities within the Watershed.

In the late 1980’s, while the conservationist movement was maturing, Steve Johonson, great-grandson of Tideman Johnson, formed the Johnson Creek Corridor Committee. This grass-roots committee was made up of neighborhood activists and early environmentalists who recognized that the Johnson Creek Watershed was a natural and cultural resource in need of help. In 1994, the committee became The Johnson Creek Watershed Council. The Council is a single organization whose focus is on the Watershed as a whole.

The Johnson Creek Watershed Councils mission is to “inspire and facilitate community investment in the Johnson Creek Watershed for the conservation, protection and enhancement of this natural resources.” It accomplishes this goal by not only being a liaison between the communities of the Watershed, and the various local, regional, state, and federal agencies governing the Watershed, but also as a liaison between those agencies.

In short, The Johnson Creek Watershed Council is a citizen based grassroots organizations, dedicated to the health of the Johnson Creek Watershed for all its stakeholders. The JCWC is a non-profit organization designated as a 501(c)(3) Public Charity. The majority of funding for the JCWC comes from grants, with a small amount funding provided by contributions. (In the fiscal year ending June 30th, 2008 government grants comprised just over 97 percent of the JCWC funding.)

Johnson Creek is the last free-flowing natural body of water inside the Portland city limits. Because of its location within an urban environment, preservation is not possible. However; conservation and stewardship of the Watershed may lead to greater utilitarian benefits. One of these benefits include the return of salmonid fish species whose populations could be maintained and controlled, through usage fees collected by the state, (eg. Fishing licenses, tags, and catch limits.) Major habitat restoration efforts now include very complex planning and engineering techniques centered around biomicry. However; the most common type of habitat restoration work in the Watershed is invasive species removal, the majority of this work is done by community volunteers.

Large scale brownfields projects, such as the newly re-meandered lower Reed Canyon, and the current re-meandering of Veterans Creek and the “Freeway Lands” project along Johnson Creek are accomplished through the coordinated efforts of local, regional, state, and federal agencies.

The effects of immediate projects such as invasive plant species removal and native species plantings are accomplished in only a few hours and have results which can be seen upon completion. Though it may take a year for the small plants and shrubs to become established, a small group of volunteers can clear and plant a hectare in a matter of hours. Intermediate projects are those which may be range in scale from a few weeks to a few years. These projects usually entail the removal of fish barriers or the re-meandering of streambeds. Projects of this magnitude require the use of heavy equipment and the services of engineers and contractors using biomimicry techniques. Biomimicry employs the detailed study of how natural systems function and their component pieces which are meticulously recreated. The Reed Canyon re-meander and Willamette River confluence projects are excellent examples of this technique. Long term projects are primarily designed to reduce the water temperature throughout the Watershed. Overstory canopy restoration is most dependent upon the growth of trees such as cotton wood, alder and douglas-fir.    

The Johnson Creek Watershed is a diverse ecosystem and has presented a unique opportunity for the city of Portland: Can human activities coincide with nature? Is it possible to integrate the needs of a diverse ecosystem with needs of humans? The answer is a resounding yes. Restoration and development throughout the Johnson Creek Watershed attempts to allow the ecosystem to manage land use and growth. When that is not possible, the needs of a healthy and diverse ecosystem are integrated into development plans. Continued conservation management, government funding, and community support will allow this unique habitat to rebound and flourish once again. A series of over a dozen parks, miles of hiking trails, designated wildlife refuges, and restored wetlands are a testament to the on-going success of careful planning, development and community involvement. Someday the salmon will return in such numbers that perhaps our children’s children will be able to once again cross the creek on their backs.

EcoWatch Daily Newsletter
Related Articles from EcoWatch
Recent Stories from EcoWatch