Davis Lake Water Quality

October 2025

The water quality and health of Davis Lake is very important to everyone. Since the early 1990's the DLLA has been focused on keeping invasive weeds under control. The primary target of our weed control efforts has been Eurasian Milfoil. In recent years, Flowering Rush has also made an appearance.

Aquatic weed control is expensive. Some funds are received from state and local agencies. Most of the expense is borne by the residents and users of the lake. The weed control work must done every year. Otherwise, the weeds spread rapidly, and it becomes difficult and more costly to get them back under control. Weeds whether they are on land or in the water can never be eradicated, just managed.

DLLA works with the Pend Oreille County Weed Board, Pend Oreille County Conservation District and the Department of Ecology to manage the weed problem. To help us, we rely on vendors who have the equipment and technical expertise to do the field work.

We have made great strides in cleaning out most of the weeds. It's been a long process but the results are good. We have gone from treating the entire lake to an area under 10 acres.

Recent treatment information and maps are below:

 

Eurasian Watermilfoil. This submerged noxious species is the primary target of treatments at Davis Lake. Note the great number of leaflets on each long, narrow leaf, this species typically has greater than 14 leaflet pairs per leaf. The very red stem is a typical trait of Eurasian Watermilfoil in our region. This species can produce flowering spikes which grow at the top few inches of the stem, submerged or emergent, but none were observed at Davis Lake. Lakeland