Stormwater Spotlight: Protecting the Puget Sound

by Erin Grenz, Chief Development Officer

The Puget Sound is the pride and joy of the State of Washington, expanding over 100 miles in an intricate system of waterways leading to the Pacific Ocean. Over 10,000 years ago, the beginnings of this waterway were dug by large glaciers slowly carving up the land under which they moved across. These dugouts filled with freshwater that carved the land more and connected to the ocean. This connection, freshwater meeting saltwater, is why the Sound is considered an estuary [1]. Today, the National Wildlife Federation has identified that the Puget Sound is home to over 3,000 species of invertebrates alone [2]. Other marine life includes fan favorites such as orca whales, giant pacific octopus, sea otter, and sunflower sea star [3]. It is also home to over 4.5 million people as of 2018. However, this home is threatened by increasing human-caused pressures. It would take a combination of effective stormwater management practices and environmental compliance from local businesses, agencies, and citizens to mitigate these threats now and in the future.

Threats to the Puget Sound

The first thing that people think of when they hear the word “Seattle” is usually “rain.” While rainfall is a vital factor in the ecosystem, its runoff has become a threat to the very environment that thrives off it. Urban development has increased the number of impervious surfaces, or surfaces that are water resistant such as concrete and asphalt. Before development, this land was covered in vegetation and porous soil that could absorb the water. Now water can no longer be absorbed due to the presence of water-resistant surfaces and instead becomes runoff, where water runs off a surface instead of being absorbed. This runoff collects trash, chemicals, and other pollutants which it carries to its destination: the Puget Sound. These pollutants collect in the Sound, contaminating the water and causing a variety of mutations and health issues in the wildlife. For this reason, stormwater has been named one of the greatest threats to the Sound [4]. Typically, this stormwater is now directed through catch basins and flumes to collection and filtration areas like detention ponds and underground proprietary systems to imitate the natural processes that slow down and filter the rainwater. These systems function best for controlling floods and mitigating pollutants when they are regularly inspected and maintained.

This threat is growing. In 1996, there were 319,409 acres of impervious surface in the metropolitan area around the Puget Sound. That expanded to 357,840 acres in 2006 and is still increasing. Based on the 2006 averages of 357,840 acres of impervious surface, 3.183 feet of annual rain, with 7.48 gallons/cubic feet, the Puget Sound Encyclopedia estimates there was 370 billion gallons of stormwater runoff from urban development alone [5]. Since 2006, the population has grown from approximately 3.5 million in 2006 to 4.5 million in 2018 and is expected to reach 7 million by 2040 [6].  It can only be assumed stormwater runoff is well over 370 billion gallons now.

Puget Sound Action Agenda

Luckily the Puget Sound Partnership Leadership Council developed a 2018-2022 Puget Sound Action Agenda written to help protect and restore the Puget Sound. The Action Agenda is designed to “complement and incorporate the work of many partners from around Puget Sound to describe regional strategies and specific actions needed to recover the Sound.” This paves the road (with permeable pavement, of course) for federal, state, local, tribal, and private entities allocate necessary resources and take proper action to protect the Sound [6].

The Agenda understands the importance of stormwater management, naming it as one of its three strategic initiatives along with shellfish and habitat conservation. They announced that one of their primary commitments is to “improve water quality and habitat by managing stormwater runoff.” They are allocating $425-$575 million of annual funding to the stormwater-specific strategic initiative to help reduce pollution from urban runoff. This still leaves a funding gap of $62-$265 million to reach the required amount to fully protect the Sound [6].

Low-Impact Development

Another beneficial movement in the Puget Sound community is a push for more Low-Impact Development (LID). LID is a land use and stormwater management system strategy with a goal of reaching near pre-disturbance hydrologic processes—AKA, allowing the water table to function closely to the way it did prior to the area’s industrialization. Some LID infrastructure includes rain gardens, which collect runoff and filter it through the presence of vegetation and soil, pervious or porous pavement which allow water to be absorbed into the pavement instead of running off, and Filterra. Filterra systems, when effectively maintained, treat runoff with planted native trees and filter media, beautifying the landscape while neutralizing impervious surfaces. There have been over 6,200 rain gardens established in the Puget Sound as part of the “12,000 Rain Gardens in Puget Sound” campaign led by Stewardship Partners and Washington State University Extension [7]. In 2018, the City of Tacoma received a $5 million grand and $3.2 million loan dedicated to improving water quality. This included installing permeable pavement [8]. In the last 10 years, the City of Tacoma alone as constructed 30 blocks of permeable pavement and five acres of permeable parking lot [9]. This pavement is regularly serviced by street sweepers to ensure the preservation of its porosity. The Washington State Department of Ecology released a 2019 plan “General Use Level Designation for Basic (TSS), Enhanced, Phosphorus & Oil Treatment” that involved the implementation of Filterra systems across the state [10]. These are just a few examples of LID systems being put in place throughout the Sound.

Protecting Puget Sound

It is crucial for businesses and municipalities to maintain their stormwater systems in order to reduce the amount of pollutants reaching the Sound.  AQUALIS understands this, which is why we put environmental health as one of our top priorities. If you have any questions regarding your business’s stormwater management, reach out to AQUALIS and see how we can help you develop a plan.