Troutdale Reynolds Industrial Park: Fall 2015 Wetland Enhancement Update

by appell 12/4/2015 9:40 AM

The TRIP 90-acre wetland mitigation area is in the open space west of Sundial Road and north of Marine Drive.

If you have been near the Troutdale Reynolds Industrial Park (TRIP) recently, you may have noticed growing site activity and a larger pond of water. This brownfield site was once considered too contaminated for development but today, Port of Portland staff and contractors are tackling this complex project. Dating back to 2007, this challenging site involves legacy contamination, existing utility infrastructure, flood management, air traffic safety concerns and natural resource protections. The Port’s work is advancing a nationwide model of sustainable industrial development that earned the 2011 Phoenix Award for top brownfield redevelopment project in the U.S.

The 700-acre site includes a combination of open space and industrial lots that will be home to future businesses and new wetland habitat as part of a mitigation plan. The plan consolidates small isolated wetlands into a much larger wetland system with greater benefits to wildlife and water quality.  TRIP also offers 1.7 mile section to the 40-Mile Loop Trail, with more additions on the horizon for recreational use. 

Located at the confluence of the Sandy and Columbia Rivers, the site provides a unique opportunity for wetland creation and enhancement, along with many challenges to restore a wetland in a dynamic, riparian environment. Extensive channel restoration is occurring as the flow of Salmon Creek is directed west of Sundial Road to form the new Sundial Channel – expanding the freshwater habitat and floodplain capacity.

As earthwork sculpted the meandering channel and lowlands, recent heavy November rains resulted in high water levels at the site during the construction phase.  This heavy rainfall during the construction phase accounts for the muddy water now temporarily ponded on site. The new site is designed to accommodate some ponding seasonally once native plants are established in the wetland. As the site matures, waters clear, and native plants take root, the water levels will recede to a shallow, marshy environment dominated by woody shrubs, limiting the expanse of open water in the basin.  The Port carefully manages water levels to ensure water quality goals are being met while minimizing wildlife attractant issues of concern for the Troutdale Airport.

Large numbers of geese are congregating in the temporary expanse of waters resulting from heavy rains. Given the proximity of the project area to Troutdale Airport, and the risk of bird/aircraft collisions, the Port’s award winning PDX wildlife hazard management team is carefully managing these waterfowl to prevent interference with operations at the nearby Troutdale Airport.  They will primarily haze birds away from the area by using loud noises, trained dogs and installing silt fencing as a visual deterrent. To ensure that the Port was able to conduct this hazing, the Fairview City Council amended their code to allow for pyrotechnics to scare birds, as well as firearms to dispatch birds in extreme situations.  City of Troutdale code was also amended to allow pyrotechnics and firearms to be used for wildlife hazing to reduce the risk to safe aircraft operations.

The wetland mitigation project includes a meandering channel and water control structure that will provide water management level opportunities.

What are “meanders” and why are they important?  You may have noticed natural curves and bends in a river while outdoors. They form through a natural process of rivers depositing sediment and the channel flow moving around it. Elevation and water volume affect meander formation – along with factors such as soil type and geology; in general, flatter surfaces have wider meanders than steep ones. These bends in the river slow flow and trap sediment, mimicking the natural hydrology of a river system, resulting in better habitat for freshwater invertebrates and higher water quality.

The wetland enhancement plan also creates a natural floodplain for the channel, which allows for water storage, nutrient absorption and slowing of water. This two-stage design applies new approaches in water management to mimic the structure and function of natural water courses. Another unique element is the use of salvaged logs and root balls anchored to the shoreline, creating habitat and woody debris found naturally in wetlands. Submerged tree roots provide habitat for fish and insects while floating logs may provide basking structure for native turtles. 

Carrie Butler, Port of Portland Ecologist, shows salvaged logs and root balls anchored to the shoreline for habitat enhancement.

Port of Portland ecologists designed sedge meadow, shrub scrub, grassland and forest habitat into the wetland mitigation plan. The ambitious planting plan establishes 98,000 individual plants of 21 different native tree and shrub species!  Contractors will plant red-osier dogwood, Douglas spiraea, swamp rose, willows and twinberry in the fall and winter of 2016. The Port will seed native grasses, such as slough grass, sedge, and soft-stem bulrush in wet areas and meadow barley, Blue wildrye and California oatgrass on hillsides, next fall once the water recedes.

Changes in elevation, stream flow and adjacency to larger rivers in a space-constrained site make the TRIP wetland enhancement project a challenge. It will take several years for the native plants to grow and establish themselves.  And, it will require ongoing maintenance to manage invasive species. The Port is working to restore a healthy, diverse and resilient wetland ecosystem that contributes to the health of the Sandy and Columbia Rivers as well as the well-being of the local community through recreational opportunities and job creation. 

Stump removal begins in economy parking lot

by timmel 8/26/2014 7:41 AM

Today, the Port of Portland moves forward with the second phase of work on the PDX Tree Obstruction Removal Project in the economy parking lot at Portland International Airport. The project began last fall with the removal of approximately 400 cottonwood trees that were beginning to encroach on federally-regulated airspace surrounding PDX's north runway.

The site will ultimately be replanted with lower-growing native trees and shrubs. The project is being executed in several phases to minimize site disturbance during wet weather months and to maximize the survivability of the new plants. The second phase, starting this week, will consist of removing stumps that were left on-site following the tree removal activity last September. Travelers and motorists should expect to see equipment removing the stumps for up to a month. 

Many of the stumps will be recovered and repurposed for habitat restoration projects. Some stumps are being given to the City of Portland and the Fairview Lake Property Owners Association. Others will be used by the Port on its own mitigation sites including projects at Troutdale Reynolds Industrial Park and Buffalo Slough. The stumps are used to create habitat enhancements such as basking areas for turtle species and to simulate naturally-occurring large, woody debris features in waterways.

When the site is replanted next fall, the trees will be replaced with more than 23,000 native shrub and small tree species such as vine maple, Oregon grape, red-flowering currant and native roses and willow. They will be planted around existing, lower-growing species of trees and shrubs that were left untouched. The images below show an artist's rendering of what the site will likely look like once the replanting has occurred.

 

PDX Tree Obstruction Removal Project begins

by timmel 9/26/2013 9:50 AM

This week, the Port began work on the first phase of a project to remove cottonwood trees growing beneath federally-regulated airspace at Portland International Airport. The site will ultimately be replanted with lower-growing, native plants. Although this first phase of tree removal took only a few days, the project is the culmination of years of planning.

Portland has a well-deserved reputation as a tree-loving city, from the iconic Forest Park to the steadfast efforts of local nonprofit, Friends of Trees. Cutting down trees is not something we take lightly. The Port was faced with a decision that was absolutely necessary to keep PDX operational well into the future.

The stand of cottonwood trees in question is located in a vegetated area within the economy parking lots. The trees lie below the regulated airspace for approaches and departures from PDX’s north runway. The trees were not yet to the point where they posed a flight safety risk, but they were beginning to penetrate other types of Federal Aviation Administration regulated airspace surrounding the flight paths. These areas are protected to prevent interference with instruments that guide approaching planes and to provide safe paths for planes should they experience mechanical difficulties.

The issue of trees encroaching on the airspace near the north runway has long been identified as a conflict that would eventually need to be addressed. In 2000, the trees were topped, providing an estimated 10-year window of protection for the airspace. Unfortunately, this was not a long-term solution. Topping trees compromises their health, making them hazardous to work around. Therefore, additional topping was not a viable option.

When master planning for PDX began through the Airport Futures process in 2007, removing the cottonwood trees in the economy lot was identified as an essential project to keep the airport operational well into the future. The Airport Futures process allowed the Port to work with the City of Portland and other stakeholders to develop a replanting plan that reflects the site’s status as an environmental zone and provides a sustainable, long-term solution that protects flight safety at PDX. When the site is replanted next fall, the trees will be replaced with more than 23,000 native shrub and small tree species such as vine maple, Oregon grape, red-flowering currant and native roses and willow. They will be planted around existing, lower-growing species of trees and shrubs that were left untouched.

While the loss of these trees is unfortunate, we have been able to complete the project in a way that was both as minimally invasive as possible and allows reuse of some of the logs and stumps for mitigation projects. The logging contractor hired by the Port used state-of-the-art equipment and technology to remove the trees, reducing the impact on the site and the amount of time during which the logging activity took place. Some of the logs cut for the project are being reserved to create turtle basking features at Port mitigation sites and some stumps will serve as large woody debris to create nearshore habitat.

The project is planned in phases to minimize site disturbance during wet weather months and to maximize the survivability of the new plants. It will take a little over a year for the site to be replanted and longer for it to become well-established. We will keep you posted on the site’s progress over time. 

 Artist's renderings of the site replanted with low-growing, native vegetation.