City of Seattle, WA

04/25/2024 | Press release | Distributed by Public on 04/25/2024 09:46

In celebration of Earth Month, learn how Waterfront Seattle is helping to keep residents, Elliott Bay, and its marine neighbors healthy

An aerial view of Pioneer Square Habitat Beach, which opened in July 2023. Photo credit: Waterfront Seattle

Blog stats: 3,000 words | 15-minute read

Editor's Note: This is a blog post from the Waterfront Seattle Program. The Waterfront Seattle Program is a collaboration between the Office of the Waterfront and Civic Projects and other Seattle departments including the Mayor's Office, the Seattle Department of Transportation (SDOT), Planning and Community Development, and Parks and Recreation.

Quick links:

Waterfront Park construction has been underway for years, and we thought as part of the global celebration of Earth Day in April, it would be a great time to highlight some of the environmental improvements the Office of the Waterfront and Civic Projects is making.

At the top of the list are marine habitat and shoreline improvements, Green Stormwater Infrastructure (GSI) that helps keep our bay healthy, and creating green connections for pedestrians and bicyclists. Thanks to intentional and innovative design, the Office of the Waterfront & Civic Projects is making sure to be a good neighbor and sustainability steward to not only residents and tourists who come visit Seattle's waterfront, but also to our marine neighbors in Elliott Bay.

A system of marine habitat improvements

Waterfront Park includes a suite of habitat improvements, not all of which are visible from the surface. These improvements support our marine neighbors, including a nearshore fish migration corridor and other elements to help marine animals thrive.

[Link]A graphic illustrating the various habitat enhancements that span the waterfront. Note: the shape of Pier 58 has not been updated to reflect the new pier under construction.

The waterfront's foundation: Remember the Elliott Bay Seawall?

It can be easy to forget the waterfront's foundation now that it is mostly out of view. The first phase of the Elliott Bay Seawall Project, which reconstructed the seawall between the area just south of Colman Dock and up to Pier 62, was built between 2013 and 2017 and it now meets current seismic standards. A key goal of the seawall replacement effort was to restore an important salmon migration corridor and to improve ecosystem productivity.

[Link]A photo of the seawall with a habitat bench, textured wall, habitat shelves, utilities, and the light-penetrating surface sidewalk above. Did you know that you were walking over the habitat bench when strolling or rolling on the Park Promenade?

When Seattle's waterfront was developed years ago, Elliott Bay lost many of its natural habitat features for fish, including sloping beaches, crevices, and vegetated hiding places for salmon. Seattle's new seawall was built to restore some of those marine habitats lost with the construction of the original seawall, with a special focus on encouraging juvenile salmon migration.

The new seawall face includes grooves and nooks to promote algae growth, shallow water and rock beds on the bay floor for fish to hide and forage at lower risk of predation, and a light-penetrating surface in the sidewalk above to provide light for marine plant growth and guidance for young salmon during their migration.

Fun fact: The new wall is 10-15 feet eastward (upland) of the original seawall to facilitate the creation of additional space for marine habitat improvements.

[Link]A graphic illustrating the habitat enhancement elements constructed along the length of the new seawall. All seawall features were designed to be integrated with other Waterfront Seattle improvements, including the future Park Promenade, the new Pier 62, and Pier 58.

The City of Seattle leveraged local expertise and hired researchers from the University of Washington's School of Aquatic and Fishery Sciences to test the effectiveness of various habitat improvement elements, which informed the ultimate design. Since the completion of seawall construction in 2017, regular monitoring has been conducted to measure the effectiveness of these habitat enhancements.

To date, Habitat Beach and the suite of habitat enhancements along the corridor have demonstrated positive results. Monitoring documentation has shown increases in the number of algae species each year, increased bull kelp growth each year, an increase in invertebrates on the beach, an increase in insects on the beach (including species that are common prey for salmon), and multiple species of salmon have been observed in greater numbers under the light penetrating surface. These monitoring results can now be used for future projects locally and worldwide.

[Link]Marine life, in this case a starfish and anemones, that have found a home on the new seawall.

A connection to the water at Pioneer Square Habitat Beach

Although a beach may evoke visions of frolicking in the water, the Pioneer Square Habitat Beach is actually part of a suite of marine habitat improvements implemented in conjunction with the first phase of the Elliott Bay Seawall Replacement Project and was designed with a special focus on restoring some of the marine ecosystem lost with the construction of the original seawall (built nearly 100 years ago), with a special focus on encouraging juvenile salmon migration.

[Link]An aerial view of the Pioneer Square Habitat Beach located between the Colman Dock ferry terminal and the Washington Street Boat Landing.

The beach helps re-establish some shoreline characteristics including shallow water, light, favorable seafloor substrates, and riparian vegetation. When migrating juvenile salmon exit the Duwamish Waterway, approximately half of them turn towards Seattle's downtown, migrating slowly along the industrialized waterfront in search of shallow protected waters typically found on natural shorelines. The first opportunity for the salmon to find refuge is at the Pioneer Square Habitat Beach. The beach serves as a gateway, guiding them into the safe haven of shallow water, consistent light, and food sources found along the new seawall's edge.

Video of salmon swimming at Pioneer Square Habitat Beach in November 2023. Video courtesy of WSDOT.

New piers, more light for migrating fish and an opportunity to remove creosote piles

During the design of the new seawall, studies on salmon behavior were commissioned by the City of Seattle to inform the design. Through those studies, it was evident that salmon's eyes do not adjust very quickly to changes in lighting, leading them to circle until nightfall at the edge of the shadow lines cast by piers. This circling leaves them vulnerable to predation, fatigue, and starvation. Salmon also tend to seek refuge as close to shore as possible.

We observed nearly 5 times as many juvenile salmon within 10 feet of the seawall than farther offshore. These observations led to the inclusion of a light penetrating surface in the sidewalk above the seawall, as noted above. Light guides the path, and also brings with it the ability for marine plants to grow, a key component of the nearshore ecosystem. All of this data also informed the new Waterfront Park pier designs.

[Link]A close-up view of the grate at Pier 62, which provides a walkable surface while allowing light to pass through to the water below the pier.

At both piers 58 and 62, rebuilt as part of Waterfront Seattle, there was a focus on removing overwater structures that shaded shallow water adjacent to the seawall. At Pier 62, along the majority of the edge of the seawall, grating (as seen in the photo above) allows light to pass through, increasing light to the nearshore salmon habitat below. At Pier 58, currently under construction, a "nearshore" opening of approximately 4,600 square feet minimizes shadows and allows more natural light to access the shallow water below.

[Link]An aerial view of Pier 62 with the grate along the eastern edge to provide light to the water and marine habitat below. Photo credit: Tim Rice[Link]An aerial view of Pier 58 with the open water area shown on the left or north side closest to the seawall.

For additional information on fish monitoring conducted by the University of Washington's School of Aquatic and Fishery Sciences, you can watch their video on monitoring in 2022 or visit their seawall research page.

Green Stormwater Infrastructure (GSI) helps keep our bay healthy

Did you know that Waterfront Seattle treats an astounding 91% of stormwater runoff volume from the new roadway surfaces along Alaskan and Elliott ways? That equates to a staggering 10.4 million gallons of stormwater annually, preventing pollution from entering our waterways.

At the heart of this innovative approach are bioretention planters strategically placed along the waterfront. These planters not only enhance the beauty of our urban landscape but also serve as nature's own filtration system, cleansing stormwater before it reaches Puget Sound.

[Link]Bioretention planter on the east side of Alaskan Way.

The groundwork for the stormwater treatment system was laid with the design and construction of the seawall project which removed dozens of surface water runoff "scuppers" that drained rainwater contaminated with pollutants from the road and sidewalk, directly into the bay. The scupper system was replaced with a buried pipe drainage system that takes stormwater from the street into buried pipes and readies it for treatment before returning to the bay.

While the benefits of the green stormwater infrastructure are focused on supporting the health of the bay, it also provides environmental education benefits since much of it is exposed to public view. The bioretention planter located east of Alaskan Way, just north of the Pike St Hillclimb, is hard to miss and features plants that thrive in wet environments that also can stand up to and filter the pollutants from runoff.

[Link]The largest bioretention planter installed as part of Waterfront Seattle improvements located east of Alaskan Way near the Pike St Hillclimb.

Keeping our new plants thriving and happy

On the land side, as you read this, thousands of plants are sprouting and blooming along the waterfront for the very first time. While the blossoms and leaves may be new, the work to provide a safe and stable environment for them to grow began long ago.

As part of the work to build new sidewalks on Alaskan Way and the Park Promenade, soil cells - modular systems under the sidewalk - were installed to provide trees and plants with suitable conditions to grow healthy roots while also protecting the urban infrastructure from tree root damage.

Soil cells work by increasing void space underground, allowing for extensive root growth, and enabling trees to access the oxygen, nutrients, and water they require to thrive. Lack of soil compaction also helps accelerate tree growth, as less energy is needed for tree roots to push through the soil as it explores for new nourishment.

[Link]Soil cells were installed along the west side of Alaskan Way S near S King St in May 2021. While no longer visible, this infrastructure is now supporting thriving plants, similar to the ones in the photo below.

In total, 150,000 new plants and almost 1,000 new trees are being planted as part of the Waterfront Seattle program. Those plants are divided between six distinct planting zones along the waterfront and the Overlook Walk. Each zone has a different palette of plants that relates to the history, culture, and ecology of that zone.

Of note, representatives from tribes have consulted with the Waterfront Seattle team on a number of native plantings included in various plant palettes that reflect our waterfront's history. Some of the native species featured include camas, salal, and yarrow. You can learn a bit more about this restoration native plants here:

This variety in planting also increases the diversity and the resilience of urban landscaping.

[Link]Landscaping planted in spring 2024 in the steel-edged planters west of Alaskan Way S near Buster Simpson's 'Migration Stage' artwork south of Yesler Way. This type of landscaping continues throughout Waterfront Park.

Through the strategic selection of plants, they also serve as riparian vegetation, meaning they filter rainwater, provide shade and cooling, and drop organic material as food for invertebrate fish and wildlife, which is a critical part of the food chain for juvenile salmon. While many new plants and trees can already be seen on the waterfront, there are more to be planted and landscaping work will continue throughout the year.

[Link]Lush landscaping on the west side of Alaskan Way S in Pioneer Square.

Providing alternative modes of travel

Among the improvements being made along the waterfront and in downtown, we are building more than three miles of new bike lanes. On Alaskan and Elliott ways, from Pioneer Square to Belltown, a two-way bike facility spanning approximately 18 blocks is currently under construction and will be opening later this year.

Nearby, SDOT is working to advance the Alaskan Way Safety Project, which will complete a waterfront bike facility extending from Pioneer Square up to Interbay.

On Pike and Pine streets, from the Pike Place Market to Capitol Hill, 20 blocks of new protected bike lanes are under construction and will be opening this summer. These connections not only reconnect nearby neighborhoods to the waterfront but also provide a greener transportation option.

These bike facilities will be greener in more ways than one, as they include planted bike buffers in many areas.

[Link]People biking along the new bike facility west of Alaskan Way in Pioneer Square, with thriving landscaping all around.

Our entire Waterfront Seattle team is dedicated to improving the environment on the waterfront through innovative design and construction.

Meet just a few of these team members through the highlights below:

Jill Macik

Environmental Manager

[Link]Jill Macik

I have been part of Waterfront Seattle since 2014…

I work with natural resource agencies and tribes to secure environmental permits and approvals for the Waterfront pier projects.

Earth Month inspires me to…

Think more critically about my personal environmental impact. Since it's spring, my mind goes to migration. I think of how the animals making this journey have been impacted by humans and ways I can mitigate these impacts, by creating habitat (native plants in my yard, birdboxes for nesting species) and minimizing lights around my house at night.

My professional background is in…

Environmental planning.

My proudest moment on this project is…

Working collaboratively with the project team, the tribes and resource agencies to expand the habitat improvements on Pier 58. The project team listened to the feedback we received and built on the enhancements installed as part of the Elliott Bay Seawall Project and included additional nearshore open water habitat for migratory salmon. It's so exciting to see this come to life as the project is constructed.

My favorite memory of working on the waterfront is…

Stepping out on the rebuilt Pier 62 for the first time and seeing so many people enjoy this new public amenity that I helped make a reality.

My favorite things outside of work include…

Enjoying Seattle's beautiful parks and open spaces with my husband and daughter, birdwatching, and sea glass-hunting.

Nick Shrope

Supervising Civil Engineer

[Link]Nick Shrope

I have been part of Waterfront Seattle since 2012…

I started as a consultant working on the design of the Seawall. I now work with project managers, construction management and inspectors, coordinating with City asset owners, resolving issues during construction, supporting the efforts to keep the project within scope, schedule and budget, developing and overseeing design revisions, and looking out for the City's best interests.

Earth Month inspires me to…

Think about my consumption and the use of plastics in the products I buy. I can make a difference by supporting products that use environmentally friendly packaging alternatives to plastic so that I can reduce my waste footprint.

My professional background is in…

Civil Engineering. I have worked for SDOT for the last 11 years focusing on the design and delivery of Capital Projects for the City. Before that I worked as a design consultant in Seattle working with local and state agencies to design roadways, bridges, and stormwater detention and water quality facilities in the region.

My proudest moment on this project is…

The opening of Alaskan Way.

My favorite memory of working on the waterfront is…

Interaction with our team members. I've learned so much from each and every one of them and have really enjoyed getting to know them on a personal and professional level.

My favorite things outside of work include…

Spending time with my family and friends, attending sports events, concerts, and comedy clubs, weight training, playing golf, and traveling.

Ticson Mach

Project Manager

[Link]Ticson Mach

I have been part of Waterfront Seattle since 2021…

I represent the Office of Waterfront and Civic Projects management team, asset owners, and stakeholders to deliver the projects on time and schedule according to the scopes prescribed in the contract. I coordinate with our environmental team to ensure construction work is compliant with permit conditions. I also work with our construction management team to resolve varying construction issues.

Earth Month inspires me to…

Inspire others to contribute to restoration efforts. After the opportunity to manage the environmental cleanup and habitat construction by the Duwamish River, I learned and came to appreciate a lot about restoring the land to its natural state. I took every chance to take out of town visitors to educate them about the cleanup effort. Earth Month provides an opportunity for many to contribute, such as picking up trash on the beach.

My professional background is in…

Project Management. I've worked for the City of Seattle Office of the Waterfront and Civic Projects for nearly 3 years as the project manager for the Pier 58 and Marion Street Pedestrian Bridge. Before joining the city, I spent 6 years working for consulting firms after I graduated from the University of Washington in Civil Engineering. I then joined the Port of Seattle for 25 years. My work at the Port of Seattle included design and project management of waterfront infrastructure such as recreation marina, container terminal, environmental cleanup, and habitat restoration.

I am most looking forward to…

Seeing kids get to play on the Pier 58 play area when it is complete and many Monday night football home games where Pier 58 will be part of the Seattle waterfront view.

My favorite memory of working on the waterfront is…

Working with everyone on the project teams who trust me and are always willing to help each other.

My favorite things outside of work include…

Traveling around the world and doing vegetable gardening in the summer.