PROJECTS

Stream Restoration
The OLWC partners with the community on projects to improve the health and function of the Oswego Lake watershed. For examples of these projects, click on the links below:

Current Projects

Projects Prior to OLWC


Current Projects

2017 OWEB Small Grants

Brighton Home Owners Association


Task 1: Invasive Species Removal
The first task needed is the removal of invasive species currently found in the drainage swales and retention pond. This includes yellow flag iris (Iris pseudacorus), Himalayan blackberry (Rubus armeniacus/discolor), Canada thistle (Cirsium arvense), and bindweed (Convolvulus arvensis). The majority of the invasive species must be removed in order to properly assess the bioswales and stormwater function, particularly the Himalayan blackberry.

Each species will be removed based on recommended best management practices and will utilize a combination of manual, mechanical, and chemical treatment. Follow up maintenance and monitoring will be required to ensure that these species have not become reestablished and that no new invasive species are introduced.

Task 2: Vegetated Swales and Wetland Function

Henderson Environmental Design, Inc. has placed a bid on assessing and restoring the function of the storm water system at the BHA greenspace (see attached document). Ideally, little sediment will have built up in the system and only planting new native species will be required. If not, a small excavator (i.e. Bobcat) may be required to remove the built up sediment.

Task 3: Replanting
After the invasive species are removed and any required excavation completed, the swales will need to be replanted. The swales were originally seeded with a mix of mostly native perennial and annual seeds. A mix of native grasses suitable for a wetland environment will be planted in the swales. A minimum of 120 live seeds per square foot are required to be broadcast by hand. Based on this calculation, approximately 7 lbs of live seeds will be required to replant the swales.

The replanting of the site will also include 1-2 gallon plants that are suitable for a wetland environment. In the summer months, the site has dry soil and a mix of sun and shade, although most of the area is in full sun. A native hedgerow will be established to provide wildlife habitat as well as privacy to the space

UPDATE: Meet the hardy crew and their 4-legged supervisors at work at the restoration site

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UPDATE: Watch this amazing time lapse capture of the restoration work in progress!

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Mountain Park Home Owners Association (MPHOA) – Tanglewood Tributary

Tanglewood tributary prior to plantings, but after creek channel alteration.

Tanglewood prior to plantings, but after creek channel alteration.

In the first of a planned series of projects to restore this 25-acre watershed in the headwaters of Springbrook Creek, restoration will focus on the restructuring and restoration of the basic hydraulics of this tributary. By constructing new storm-water management systems, constructing a stable stream plan, and a profile that corrects the current erosion a new wetland will be created as the foundation for a sustainable riparian environment. Appropriate new plantings in the wetland and in adjacent parts of the upland will be part of the ongoing removal of invasives and replacement with native vegetation.

Details of the Solution
The proposed project will build upon the MPHOA Master Plan for Common Property and work accomplished to date to bring the watershed of Tanglewood Park Tributary to a high level of restoration consistent with the Oregon State Conservation Strategy, Intertwine Regional Conservation Strategy, Oswego Lake Action Plan, Lake Oswego City Sensitive Lands Program and The City of Lake Oswego Clean Stream Plan. This project also will serve as a model for planned future restoration of five other Springbrook Creek headwater watersheds that are located within Mountain Park. Restoration also will benefit adjacent areas, specifically: Springbrook Creek, all of the Oswego Lake watershed and the Tryon Creek State Park Wildlife Corridor. As such the project is wholly integrated within the regional environmental restoration program. Linkages will be implemented through the creation of the Partners Council, an advisory group to be made up of all organizations that are formally linked to this project. The physical work that is proposed within this project will involve the following elements.

    1. The areal extent of the proposed project will be the primary riparian areas along Tanglewood Park Tributary and other affected upland areas within the watershed. This area is approximately 5 acres of the Triangle Park Tributary watershed and includes most of the MPHOA Common Property in that watershed. The project will not modify any homeowner property. However, homeowners will be involved in planning all restoration and will have opportunities to coordinate restoration on their property with this project. Appropriate native plants for homeowner properties will be provided by MPHOA.
    2. The contributing sources of storm-water runoff from residences and paved areas that discharge in the area will be identified and new water management facilities will be constructed. Two major street storm-water outfalls have been identified and these will be rebuilt using on-site measures to address source control, flow control and to improve water quality and quantity as a major source of water for a restored wetland. MPHOA and OLWC will actively partner with the City of Lake Oswego in this aspect of the project and will be implementing these water retention facilities using the highest standard of contemporary and future approaches.
    3. A major element of work will be to plan, design and implement a realignment and reconstruction of Tanglewood Park Tributary for a length of approximately 550 feet. Henderson Environmental Design-Build Professionals have completed a conceptual design for this restored tributary and will be engaged to complete the project. The objectives of the stream work will be: a) to maximize wetland in the watershed by retaining all natural groundwater flows and stormwater delivered to the site; b) to reconstruct the deeply incised lower channel, raise the vertical profile with grade control vanes and stabilize the channel with native vegetation.
    4. A program for removal of invasive plants and re-vegetation with native plants will be undertaken for the riparian and upland areas within the project area. As part of its Master Plan, MPHOA has already implemented some invasive plant removal and native plant restoration in the watershed (immediately SW of Project area). The new wetland is expected to cover up to 1.5 acres. All invasive plants will be removed from this area and replanting will be with native trees, shrubs, and forbes in accordance with the HOA’s and City of Lake Oswego’s approved native plant list(s). Replanting will consist of a mix of potted and bare root native plants installed every 9ft. Native species installed will include vine maple (Acer circinatum), Douglas spirea (Spirea douglasii), ocean spray (Holodiscus discoulor), Pacific nine bark (Physocarpus capitatus), Douglas fir (Pseudotsuga menziesii), and western hemlock (Tsuga heterophylla).
    5. The existing MPHOA Trail System currently provides community access to the Tanglewood Park Tributary watershed. Modification and reconstruction of the trail system to improve access and to complement the restoration will be part of this project. In addition, interpretive educational signage will be installed to realize the outreach potential of the project.

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2015 Watershed Enhancement Projects

The Oswego Lake Watershed Council (OLWC) is pleased to announce a partnership with the City of Lake Oswego to improve the watershed on three private properties within the Oswego Lake Watershed. Under changes in the Sensitive Lands ordinance the City Council directed Parks budget funds be directed towards public property to enhance and maintain the health of the watershed. These funds will also help private property owners enhance the health of the watershed on private lands. The City has contracted with OLWC to create a program that not only benefits the homeowner whose property contains natural watershed resources, but benefits the entire community by restoring a healthy functioning watershed as a common good.

OLWC, whose mission is to conserve, restore, enhance and maintain watershed functions to achieve and sustain a healthy watershed, identified three demonstration sites that would help the City achieve the goal of improving watershed function on public and private property throughout the City. The sites were chosen to demonstrate how this program would work for three property types of high environmental value in different areas of the city.

The criteria used to identify these sites were:

  • Property had running water at least part of the year (riparian sites)
  • Property was adjacent to City natural areas
  • Property was degraded by invasive species and other effects of urbanization

For these demonstration projects, the property owners were not involved in the selection of the sites. They were approached after their property was identified as being high value sites for enhancing watershed health. All three were happy to be involved in the demonstration projects.

To ensure longevity of the enhancement project, property owners sign an agreement to maintain the property in the future. The City provides OLWC funds to help with maintenance for three years following the initial work. Monitoring of the enhanced properties will take place beyond the three year maintenance timeline to ensure properties are not taken over by invasive species or become degraded.

Once these demonstration projects are done, the OLWC will work with Neighborhood Associations to identify properties that would benefit the community and provide a mechanism for property owners to apply for this program. Community members are welcome to help with OLWC projects. For further information visit: http://www.oswegowatershed.org.

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Springbrook Park Repair and Restoration

Friends of Springbrook Park provides ongoing preservation and protection services for this a 52-acre urban nature park (map), in partnership with the Uplands Neighborhood Association, the schools, and the City of Lake Oswego Parks & Recreation Department, which manages and maintains the park. Along with the Parks and Recreation Department, Friends organizes volunteers to remove invasive plants, restore and replant cleared areas, and improve and maintain trails. CLICK HERE to learn how you can be involved.

Friends of Iron Mountain “1000 Trees” Ivy Removal Events

Friends of Iron Mountain schedule work parties each Spring and Fall to remove invasive English Ivy – organizer Mick Buck reports “940  trees have been freed from their ivy encroachers so far.” CLICK HERE to learn how you can join this group for future events.

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5th Grade Watershed Program

The Oswego Lake Watershed Council (OLWC) has partnered with Friends of Tryon Creek State Park to develop a watershed field study program for all Lake Oswego School District fifth grade students.  This program has been designed to instruct the students on watershed function, particularly in areas where there is not a lot of impact from development.  As the students explore the park they are instructed on the function of plants and soils in maintaining clean water in streams, rivers and lakes.

6th Grade Watershed Program

The Oswego Lake Watershed Council has partnered with the Lake Oswego School District and Portland State University Center for Science Education to develop a place based watershed engineering and design curriculum for the 6th grade science classes at both Lakeridge and Lake Oswego Junior High Schools. This program links with the 5th grade experience through making comparisons between natural and urban/suburban watershed conditions.  The 6th grade students analyze their school campuses in order to understand the effects of the built environment on watershed function with a targeted focus on the effect of impervious surfaces.  The students then engage in engineering activities to create Low Impact Design (LID) mitigations for these impervious surfaces. The OLWC and City of Lake Oswego support this curriculum by supplying local learning materials including maps, rainfall data, and a 6th grade Watershed Design Manual adapted from the city’s materials.

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Springbrook Creek, in the Oswego Lake Watershed

Projects Prior to OLWC

Earth Day 2001 Project:
Springbrook Creek Clean-up Event

On Saturday, April 21, 2001 volunteers worked from 9:00 am to Noon:

  • ivy pulling
  • blackberry digging
  • trash pick-up

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2003 Springbrook Creek Fish Passage Project (REACH FIVE)

  • Project Need: A fish passage barrier was created by a 3-foot high dam forming an in-stream pond on Springbrook Creek.
  • Project Goals: The project goals were to restore fish passage through the site of an in-stream dam and pond.
  • Project Objectives: The project objectives were to use natural channel design techniques, remove the dam and in-stream pond, create natural riffle/pool sequence, improve fish and wildlife habitat, protect fish during construction, and meet ODFW fish passage guidelines.
  • Approach: This project is a demonstration of the successful application of a geomorphic approach to stream restoration using natural channel design techniques.
  • Project Funding: The City of Lake Oswego Engineering Division funded the project.
  • Project Management: The City Engineering Department established the restoration objectives, required the geomorphic approach, led the design team, reviewed the design, and inspected construction implementation.The City project manager was Andrew Harris. The Project Engineer and designer was Russ Lawrence, PE of Pace Engineers. Mr. Lawrence designed the step/pool sequence and low flow fish passage structures. Russ and Andy performed the geomorphic assessment and site survey.

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2003 Springbrook Creek Fish Passage Project (REACH ONE)

  • Project Site: This restoration was located below the railroad box culvert 750 feet above the mouth of Springbrook Creek on Oswego Lake (REACH ONE).
  • Project Need: A fish passage barrier was created 3-foot drop at the downstream lip of the railroad culvert. The depth of flow in the culvert prevented fish passage through the culvert during low flow conditions.
  • Project Goals: The project goals were to restore fish passage into the culvert and through the culvert during low flow conditions.
  • Project Objectives: The project objectives were to use natural channel design techniques, create natural step/pool sequence, improve fish and wildlife habitat, protect fish during construction, and meet Oregon Department of Fish And Wildlife (ODFW)  fish passage guidelines.
  • Approach: This project is a demonstration of the successful application of a geomorphic approach to stream restoration using natural channel design techniques.
  • Funding: The City of Lake Oswego Engineering Division funded the project
  • Project Management: The City Engineering Department established the restoration objectives, required the geomorphic approach, led the design team, reviewed the design, and inspected construction implementation. The City project manager was Andrew Harris. The Project Engineer and designer was Russ Lawrence, PE of Pace Engineers. Mr. Lawrence designed the step/pool sequence and low flow fish passage structures. Russ and Andy performed the geomorphic assessment and site survey.Fish passage barrier at railroad box culvert

Before Construction: June 1, 2000 (slides below)

  • The jump is 20-inches
  • The top of the jump is 15-feet wide.
  • The large boulder in the foreground of the photo is 13-feet from the opposite wall.
  • The culvert is 7-feet 9-inches wide and 7-feet 9-inches tall.
  • Low flows are very shallow across the flat bottom of the culvert.

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During Construction: September 16, 2003 (slides below)

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Post Construction (slides below)

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