Each summer during especially hot weather, Juanita Bay can experience high concentrations of bacteria or other contaminants that can result in the closure of Juanita Beach Park for several days.
Juanita Beach is one of the city’s most popular parks for swimming because of its sandy beach and summer lifeguards. The city understands that closing the beach is very impactful to all users and staff works hard to prevent closures from occurring. We frequently receive questions from park users about why closures occur and how we can prevent them. I wanted to summarize how the city works to address the issues at Juanita Beach Park.
The city has researched the causes of the water quality problems in Juanita Bay. Studies have found that the unique characteristics of Juanita Bay make it more susceptible to closures than other areas of Lake Washington. Juanita Bay is shallow and the prevailing winds from the southwest trap silt, gravel and bacteria in the bay. As a result, water in Juanita Bay is warm and does not mix as quickly or as thoroughly with water in other areas of Lake Washington. This creates conditions that result in periodic water quality challenges.
Other contributing factors are sediments and contaminants that often flow into the bay from nearby Juanita Creek. Any contaminant in Juanita Creek can adversely affect the water quality in Juanita Bay due to its shallow depth and poor circulation. Sources of fecal contaminants in Juanita Bay can include broken sewer lines, leaking or failing septic systems, wildlife or geese droppings and pet waste. Unfortunately, many well-meaning park visitors feed waterfowl and pet owners do not always keep their dogs away from the swimming area or dispose of pet waste properly.
The combination of factors: the poor circulation of the bay, prevailing winds pushing bacteria to the north, sediment accumulation, warm temperatures in the shallow bay, duck and geese feces, pet waste, and surface water runoff from the creek and shoreline properties result in the periodic closures.
City staff implement multiple water quality improvement strategies every year. To keep park visitors safe, the city works with the King County Swim Beach Monitoring program to actively monitor bacteria levels and to find and address bacteria sources over time. These efforts will continue until water flowing from Juanita Creek consistently meets state standards.
Kirkland also partners with surrounding cities and the U.S. Department of Agriculture to manage the goose population. Juanita Beach Park was designed to be less inviting to waterfowl and park staff actively disrupt roosting. The beach is also cleaned whenever possible, staff work to keep visitors from feeding ducks and geese and Kirkland has ramped up enforcement of leash laws and pet waste disposal at the park.
In general, Lake Washington has good water quality. Studies show that significantly improving the water quality in Juanita Bay requires more water exchanged between the open water of the lake and the bay. While there are engineering solutions that can increase this water exchange, they are hugely cost prohibitive to install and operate and too invasive to get state or federal approval due to impacts to threatened Chinook salmon.
However, the studies also identified that reducing fine sediment deposits along the beach and reducing direct runoff to the bay and creek from fecal material from the park and other adjacent properties would provide the highest and most cost-effective benefits in reducing bacteria concentrations at the beach. Kirkland’s surface water management program is focusing on these actions.
While there are no simple solutions today, the city remains committed to improving the water quality of Juanita Bay and keeping the beach safe for all forms of recreation. New techniques and new technologies emerge every year and Kirkland will continue to explore innovative ideas and solutions to eliminate future closures.
Jon Pascal is a Kirkland City Council member and chair of the Public Works, Parks, and Human Services Committee.