2025 Lake Sediments Depths

Paul Slota, Howard Fenton and David Liebl, 1/15/2025

On January 15, Howard and I measured the lake depth and sediment layer at 6 locations on Lost Lake. We followed the plan developed by the Monitoring Committee (attached).

The conditions were sunny with temperatures in single digits rising into the teens. The ice depth was about 6in with about ½ inch of snow covering the lake. The day was scheduled to coincide with a Wisdom Prairie workday adjacent to the lake as an added safety precaution.

The lake has two drainage culverts that allow surface runoff and sediment to enter the lake. The north culvert is at the northern end of the lake and drains runoff from the north. The northwest culvert is also at the top of the lake but on the west shore and drains the northwest part of the property. A third inlet is on the west shore and drains the neighborhood to the west.

Six points were sampled using a manual ice auger and a specially fashioned PVC pipe for taking measurements. Two depth measurements were taken at each point. A measurement from the surface level to the top of the sediment layer and a measurement from the surface level through the sediment layer to the lake bottom. Subtracting the distance between the surface to sediment layer from the total distance from the surface to lake bottom equals the depth of the sediment layer. Two GPS coordinates were taken at each sampling point (iphone compass and iphone google maps coordinates).

Summary

Sediment levels were greatest (2ft, 6in) at the top of the lake (north) where the two culverts allow runoff and sediment to enter the lake. Sediment levels were the least (7in) at the southern end of the lake. Levels in between diminished from north to south.

Lake depths (surface to the sediment layer) ranged from 8ft 3in at the top of the lake to 9ft throughout much of the lower (southern) two thirds of the lake. The most recent reading of the Lost Lake staff gage indicated that the ice surface was 6.85 feet above bottom at that point.

Specific Sampling Points (north to south)

Sediment depth 2ft 6in
Top of the lake (north shore)
Approximate distance from the north culvert 50ft
Coordinates: Google Maps: 43.1219718, -89.4553889  Compass 43°7′19″ N  89°27′21″ W
Depth to sediment layer 8ft 3in
Depth to hard bottom 10ft 9in. Sediment depth 2ft 6in

Sediment depth 9in

Taken on a diagonal north from the peninsula to the east shore.
Approximate distance the north culvert 125ft
Coordinates: Google Maps: 43.1217295, -89.4553060  Compass 43°7′18″ N  89°27′19″ W
Depth to sediment layer 6ft 4in
Depth to hard bottom 7ft. 1in Sediment depth 9in

Sediment depth 1ft 9in

Taken on a diagonal north from peninsula to the east shore.
Approximate distance the north culvert 125ft
This point is closest to the northwest culvert, may receive additional sediment??
Coordinates: Google Maps: 43.1216336, -89.4552601 Compass 43°7′17″ N  89°27′19″ W
Depth to sediment layer 7ft 3in
Depth to hard bottom 9ft. Sediment depth 1ft 9in

Sediment depth 1ft 6in

Taken on a diagonal south from the peninsula to the east shore
Approximate distance the north culvert 250ft
Coordinates: Google Maps: 43.1213536, -89.4552125  Compass 43°7′16″ N  89°27′18″ W
Depth to sediment layer 9ft 1in
Depth to hard bottom 10ft. 7in Sediment depth 1ft 6in

Sediment depth 1ft 2in

Taken on a diagonal south from the peninsula to the east shore
Approximate distance the north culvert 344ft
Coordinates: Google Maps: 43.1211204, -89.4556407 Compass 43°7′16″ N  89°27′20″ W
Depth to sediment layer 7ft 6in
Depth to hard bottom 8ft. 8in Sediment depth 1ft 2in

Sediment depth 7in

Taken at the bottom of the lake about 141ft from the south shore, east of a small peninsula on the west side of the lake
Approximate distance the north culvert 490ft
Coordinates: Google Maps: 43.1207357, -89.4559726 Compass 43°7′15″ N  89°27′22″ W
Depth to sediment layer 9ft
Depth to hard bottom 9ft. 7in Sediment depth 7in