Waves & Erosion at Newman Lake

Waves and Erosion

The topic of erosion and the cause of that erosion has been debated for years at Newman Lake. 

Is it the level of the lake that causes excessive erosion? Is it the type of boat or creation of the waves that cause excessive erosion? Or a combination of both?

Newman Lake experiences seasonal water quality problems such as low dissolved oxygen and algae blooms. These conditions can be harmful to fish, humans and pets. Shoreline erosion releases soil and nutrients to Newman Lake, which contributes to these conditions during the critical summer months.

Reduced erosion equates to improved beach quality for recreation and habitat, requires less costly protective measures and leads to an enhanced watershed for property owners and recreational users.

Study on waves by Spokane Department of Conservation

The Spokane Board of County Commissioners funded a Spokane Conservation District study researching wave impacts on Newman Lake this year (2020). Part of the research involves surveying boat owners at the public launch, photography of the entire shoreline before and after a season, monitoring the type of boat and the wave that boat generates at different locations on the lake, community surveys and more.

All of this information will be presented to the Board of County Commissioners at the end of 2020 or beginning of 2021.

The Board of County Commissioners will review the information and are determining whether to impose a ban on the “creation of waves” at Newman Lake.  They are NOT considering banning boats, but the creation of the waves that impact our shoreline at Newman Lake. They are also considering a “trial” or “temporary” period for this ban, and only at Newman Lake.

The BOCC has also received information from the Spokane County Marine Sheriff, commenting that Newman Lake receives the highest number of complaints.



Wakeboats: Concerns and Solutions for Potential Lake Degradation

Newman Lake Wave Study Report

In September 2019, the Spokane County Board of Commissioners appointed the Spokane Conservation District (SCD) to lead an effort to investigate the wave generated erosion issues at Newman Lake. The SCD study observed, collected data, and quantified shoreline changes through the seasons. The SCD created a comprehensive study which included a full-scale inventory and characterization of existing shoreline conditions around Newman Lake, a survey of the lake’s residents with questions about their boat use, weekend surveys of public boat launch use, a study of waves created around the lake with continuous recording of wave heights, and monitoring of specific erosion locations around the lake which helped demonstrate change over time.