Large wakes from powerboats speeding down Newman Lake are pounding the shoreline, leading to severe erosion in some areas.
At the Tyler home on the west side of the lake off Peninsula Drive, about 30 feet of beach has been lost in the past 15 years, said Walt Edelin, a water resource manager for the Spokane County Conservation District. The sand was eaten away to the point that there was a 2-foot drop-off at the shoreline instead of a gradual decline into the water.
The property owners teamed up with the Conservation District for an erosion control project that should stop the beach from continually shrinking out from under two beachfront bunk houses. “Since we have those two cabins on the beach, we had to do something,” said Ed Tyler.
The district got a $30,000 grant from the Department of Ecology to design and install a solution. The property owners also contributed several thousand dollars to the project. Several “bio logs” made of coconut fiber were installed along the water’s edge. Sedge and rush plants were planted directly into the logs to put down roots. A row of coyote willows and dogwoods were planted just inches from the edge of the beach, which is now just a narrow patch of sand.
The idea is that the bio logs will trap sediment as they slowly decompose. “It will turn into soil at some point,” Edelin said.
The efforts didn’t stop there. The property owners rearranged their docks to help protect the shore from wakes. Log rafts were put in the water parallel to the shore to absorb the wake energy. The rafts are anchored to the shore with ropes and chains. When a wake hits them, the logs bounce in the water as the wave washes over them. The water between the log rafts and the shore is noticeably calmer than the water in the open lake.
Edelin said the Conservation District is looking for other property owners on the lake who are interested in doing something similar. “It’s a demonstration project to show we can do this without putting in bulkheads,” he said.
The Newman Lake Property Association organized a meeting Wednesday at the Tri-Community Grange to present the project to residents. “It’s quite a problem,” association board member Karen Stebbins said of the erosion issue. “It’s pretty widespread.”
The erosion is caused by boats with bladders, the kind that is often used by wake boarders, Edelin said. Bladders are large tanks that can be filled with water to make the boats ride lower in the water and create more of a wake.
A new public boat launch was recently completed on the east side of the lake, and boat traffic is up. “It has led to increased use of the lake by bladder boats and fishermen too,” Stebbins said.
The home on Peninsula Drive has been owned by the same family for 100 years and never had a problem with erosion until the powerboats came to the lake, Edelin said. Normal storms on the lake didn’t seem to have much effect, he said. “This beach survived all those storms for decades,” he said.
Busy summer weekends can create a steady stream of wakes coming ashore continuously. “It’s just from these bag boats and the constant assault on the shoreline,” said Tyler. “It’s just like the ocean. Some people are losing trees.”
Tyler said he has asked the Spokane County commissioners to create rules to help prevent erosion but was unsuccessful. “We need to have some kind of regulation in place to protect these shores,” he said.
The dirt and sand eroding from the shore is also creating water quality problems, said Patty Tyler. “They’re not making lakes anymore,” she said. “We have to protect the ones we have.”