If you need to dump your black or gray water tanks near Shadow Lake, there are several options in the surrounding areas. Issaquah Village RV Park is a convenient site with a freshwater fill, a hose for flushing tanks, and a trash bin. Bryn Mawr Beach & RV Park is another option with dumping facilities and fresh water fill. Vasa Park Resort also provides on-site waste disposal and fresh water fill services. For those willing to drive a bit further, the KOA - Seattle / Tacoma KOA Campground also offers dumping stations.