Monitoring and Taking Care of a Site After Watershed Restoration

Photo shows three scientists in waders, one with a City of Portland safety vest, are walking down a path to a stream.
For years, Environmental Services checks on how well watershed functions are recovering following restoration of a site. This monitoring provides essential data for future projects and allows us to make adjustments to keep the site on track to recovery.

Early Monitoring Starts Even Before Restoration

Before a project is even started, Environmental Services’ monitoring team is studying the project site. What we measure and how often we measure it is driven by the size and goals of the restoration project. Pre-project monitoring gives us baseline data.

Baseline data tell us about the current condition of the project area and how well or poorly it is providing the needed watershed functions such as flood control, fish habitat, or water quality protection (to name just a few). The restoration team of engineers, biologists, and other watershed scientists use the baseline data to design the restoration project and, in the future, to track the site’s progress.  

For more information on why we collect data, visit the Portland Area Watershed Monitoring and Assessment Program webpage.

Monitoring Phases

Once the site is restored, Environmental Services begins its monitoring phases. For more than a decade, we monitor the site to answer important questions like:

  • Was the project built as planned?
  • Is it working as expected? For example, are the plants thriving? Are we finding salmon now when before we were not?
  • Are we seeing the benefits described in the project objectives happening — how fast and how well?
Photo shows a creek winding through brown space that is a recently completed restoration site.
In 2007, restoration work finished up on Schweitzer Wetlands on Johnson Creek in southeast Portland. A new creek channel meanders through the site, creating pools and gravel beds for fish and amphibians to feed, breed, and rest. Environmental Services' scientists have been monitoring the site for more than a decade.

Phase I: Project Implementation and Establishment, Years 1 to 5

Photo shows newly restored creek channel with logs protruding from stream bank and water flowing.
This 2007 photo of Schweitzer Wetlands shows how a part of the creek looked shortly after restoration work finished.

Monitoring work is most intense during the first five years after a site is restored. Restoration work often disturbs the land and removes the plants. This makes the site vulnerable to erosion, storm damage, or invasion by invasive plants. During this first phase, new plantings require the most care. Staff frequently visit the site to check on its progress and replace plantings if needed. If a large storm erodes a part of the stream, staff can make repairs. Environmental Services spends time and resources during this time to actively manage the site to make sure the project was built as designed and is on a path to success.

Phase II: Project Effectiveness, Years 6 to 10

Photo shows a creek partly obscured by the plants growing along its banks.
The same photo location of Schweitzer Wetlands in 2013 shows that plants are established.

After the first five years, new plants at a site are established and the trees are beginning to mature. The new trees are starting to provide shade, but it will still be several decades before they can provide in-stream large wood for habitat. The project is considered stable. Site management decreases, and nature takes its course.

Our monitoring activity switches to collecting data on the characteristics that change slowly. For example, aquatic macroinvertebrate communities – or water insects – take time to recover and become more plentiful. Their presence and numbers tell us how healthy conditions are on and upstream from the site.

Phase III: Project Validation, Year 11 and beyond

Aerial image of creek meandering through a green space full of trees and plants.
Today, the Schweitzer Wetlands are home to many birds and wildlife. Environmental Services continues to check the site annually for invasive species and erosion.

After 10 years, the plants are growing well on their own and much of the natural cycle is resuming. These mature sites are self-sustaining and require much less human intervention. Over the next decades, older trees will die and become snags – a dead or dying tree often without a top that provides habitat for birds and wildlife – or downed wood in the stream. This cycle provides food and habitat for native fish and wildlife.

At this point, our scientists have a good sense of whether a project has met or is on track to meet the original objectives, and any major actions to get a site back on track are done. Still, Environmental Services continues to visit every year to check for erosion or invasive plants.

What Does Monitoring Work Look Like?

During a site visit, Environmental Services field scientists will gather lots of data. A few examples include:

Two scientists stand in a creek working with tools to install temperature monitoring equipment.
Field scientists install temperature monitoring equipment.
  • Measuring the temperature of the water in the stream. Cold water is essential for salmon and other aquatic life, so taking actions that keep our streams cool is often a key part of our projects.
Photo of a tiny mayfly larvae on a person's fingertip.
We count the number and types of aquatic insects, like this mayfly larva, to learn about the stream's health.
  • Taking an inventory of the variety of aquatic macroinvertebrates or water insects that live in the stream. Aquatic insects are an excellent indicator of stream health because they are sensitive to a wide range of threats. Counting and identifying the aquatic insects such as dragonfly and mayfly larvae over time helps us see if conditions are improving.
  • Measuring the size of rocks along the stream bed to learn about how fast water can move in certain parts of a stream. Flowing water can be very powerful, but measuring the speed of water during a flood is dangerous. By measuring the rocks, scientists also can see what sort of habitat is available for the aquatic insects that make their home along the stream bed.
  • Checking groundwater levels to understand how close water is to the surface. Areas with water levels close to the surface can support wetlands. This helps us understand what sort of plants will thrive at the site.
Photo shows a young cutthroat trout above a scale for measuring length.
Fish surveys count the number and type of fish found at a location.
  • Surveying the extent and depth of water during floods. Many of our projects aim to increase flood storage at a site in order to reduce flooding on nearby properties. When large storms occur, staff will visit sites to see where flooding is happening and how restored sites perform under these conditions.
  • Conducting fish surveys. Many projects aim to improve habitat for fish, so our fish biologists survey to learn more about where certain species, like salmon and trout, can be found.
  • Checking on the plants. Staff survey the abundance of different types and numbers of tree, shrub, and grass species across the site and check for any invasive plants that are becoming a problem.

We combine and analyze all that data from many sites around Portland. Using that information, our scientists generate a report card for each of Portland’s watersheds so Portlanders can track the health of their rivers and streams. Learn more about the watershed report cards and what goes into the grading.

Monitoring Helps Us Improve with Each Project

Restoration monitoring is a critical component of “adaptive management.” To improve the effectiveness of our conservation and restoration actions, we need to collect data on our projects and evaluate how effective each project is at improving the conditions it was designed to address. With monitoring data, we learn from each project as it progresses and then incorporate that learning into the next project’s design. This cycle helps ensure our actions are as beneficial and cost-effective as possible.

Find current watershed restoration projects either in design or construction.

Remote Media URL

Explore restoration projects that Environmental Services is now monitoring.