Did you know that Magnuson Park’s large wetlands were only established 15 years ago? It is difficult to imagine, when strolling through this lush and diverse ecosystem, that same drenched trees, ponds, and meadows were previously covered in asphalt as part of the Sand Point Naval Air Station.
These areas formerly included marshes and a Douglas fir and alder woodland. The previous “Mud Lake” and stream considerably dried up after Lake Washington was lowered in 1916. As a result, the habitat was transformed, but it was still a suitable location for a new naval aviation station.
The Navy acquired the property in 1920 and built a base of operations for its air fleet there. 1.4 million cubic yards of earth were used to level the area, and most of it was covered with pavement. The facility was deactivated in 1970, and in 1975 it donated 195.6 acres to the city for a new park that was first named Sand Point Park but was subsequently renamed Warren G. Magnuson Park in honor of the senator who had pushed for the park’s establishment. Later, it was enlarged to become Seattle’s second-largest park, with a total of 350 acres.
The park was planned in many ways during the 1990s and earlier, but it wasn’t until 2001 that the Seattle Berger Partnership’s concept was accepted by the city council. The plan’s main component was a large wetland complex. The Master Plan was finished after three years of legal proceedings and obstacles, and construction started.
This plan was heavily influenced by Guy Michaelsen, Principal at the Berger Partnership, who recently visited with our Senior Gardeners and a few other staff members to discuss the wetlands, their history, and how we can take good care of them.
Ten acres of freshly designed wetlands and four acres of restored wetlands may be found in the Magnuson Wetland Complex. They were formally created to lessen the effects of building the additional sporting fields that were also included in the design. The whole system has the capacity to hold more than 5 million gallons of water in ponds, wetlands, under the artificial sports fields, which helps lessen the amount of non-point source pollution entering Lake Washington from the nearby communities and roadways.
Magnuson Park’s wetlands are excellent in supplying ecological services. According to one research, “when stormwater runoff passes through wetlands, the wetland complex decreased total suspended particles by 94%, fecal coliform bacteria by 99%, and increased dissolved oxygen by 32%.”
What else makes the wetlands unique? The University of Washington’s Dennis Paulson, a dragonfly specialist, has discovered 19 different species of dragonflies in these wetlands, more than anywhere else in Seattle. Pacific Tree Frogs live in the ponds as well, and their larval population has grown by 255% as a result of natural processes that have transformed certain vernal ponds into suitable habitat. With 222 kinds of birds recorded thus far, the park is also a haven for birds.
It is simple to understand how the wetlands in Magnuson Park are a significant asset to our community from an ecology standpoint. Magnuson Park is a tale of human and natural resilience, tenacity, and adaptation from healthy environment to Navy base and back to healthy habitat. What will happen during the next 15 years?