How deep is South Lake?

South Lake reaches a maximum depth of 88 feet in the Michigan DNR Inland Lake Contours survey. Most of it is far shallower: the survey charts 8 closed depth contours over about 91 acres, and half of that water sits inside the 40 ft line. The 88 ft figure is a single recorded sounding rather than a closed contour, so the deepest line you can actually trace on the map is 80 ft.

Where is the deepest part of South Lake?

The deepest charted water on South Lake lies inside the 80 ft contour, toward the southwestern corner of the lake. That contour encloses 1 acres, 1.1% of the mapped water, so it is a small target on a small water, the depth chart above gives the contour to line up on.

How much of South Lake is shallower than 40 feet?

About half. The 40 ft contour encloses 34 acres of the roughly 91 acres inside the outer 5 ft line, so the other half of the water is shallower than 40 feet. The sharpest drop is between 30 and 40 feet, where the mapped water sheds 25 acres.

How accurate is this South Lake depth map?

The contours come from the Michigan DNR Inland Lake Contours survey, retrieved August 2026 and last rebuilt on August 19, 2026. Depths change over time with water levels and sediment, so treat this map as a planning guide for fishing, and never use it for navigation. Acreages are computed from the published contour geometry, not from a separate area survey, so read them as close approximations.

Michigan lake depth maps

South Lake depth map

South Lake in Washtenaw County, Michigan reaches a depth of 88 feet. South Lake is charted here across 8 closed depth contours, from the 5 ft line down to 80 ft, enclosing about 91 acres of water. Half of that water lies inside the 40 ft line, and only 1 acres lie inside the deepest one. Every contour is on the interactive map below, free and without an account.

Data: Michigan DNR Inland Lake Contours (public record). Contours closed, checked and area-computed by Jordan Carter, founder of GilledIt · page updated August 19, 2026

South Lake depth chart: 8 depth contours from 5 to 80 ft

Data: Michigan DNR Inland Lake Contours (public record), retrieved August 2026 · depths change over time · not for navigation

South Lake depth chart data: water enclosed by each contour
Depth contour	Water inside it	Share of mapped water
5 ft	91 acres	100%
20 ft	79 acres	86%
30 ft	59 acres	65%
40 ft	34 acres	38%
50 ft	20 acres	22%
60 ft	8.4 acres	9.2%
70 ft	3.7 acres	4.1%
80 ft	1 acres	1.1%

Acreages are computed from the closed Michigan DNR Inland Lake Contours contour rings, with islands subtracted. Shares are of the 91 acres inside the outermost charted contour (the 5 ft line), which is the outer edge of the mapped water, several state files carry no 0 ft shoreline line, so this is not the same as a share of the lake's published surface area. The survey also records a 88 ft sounding, marked as a point rather than a closed contour, so it is not charted as a band.

Fishing South Lake: a stepped drop into deep water

Inside its outermost 5 ft contour the survey charts about 91 acres of South Lake, with the 40 ft line enclosing half of it, so the bottom steps down contour by contour into the deep basin rather than shelving flat or plunging all at once. The sharpest change on the chart is between 30 and 40 ft, where the mapped water loses 25 acres in 10 ft of depth, that band is the contour to work first, because it is where the bottom stops being flat. 1 acres, 1.1% of the mapped water, lie inside the deepest 80 ft contour, toward the southwestern corner of the lake. At 88 ft this is two-story water: the basin can stay cold below the summer thermocline while warm-water fish stay up on the 5-to-40 ft ground, and the fish that move between the two do it along the 30–40 ft break at first and last light.

Ice fishing on South Lake

Deep water like South Lake freezes later and less evenly than the shallow lakes around it, and the winter bite sets up on the first real break, not out over the 80 ft hole. That edge is the 30–40 ft band on the chart above, where 25 acres of bottom tilt away, and panfish and walleye work up and down it through the day. By late ice the fish push back onto the 5-to-40 ft flat. Check ice thickness locally before you walk out.

South Lake depth map FAQs

How deep is South Lake?: South Lake reaches a maximum depth of 88 feet in the Michigan DNR Inland Lake Contours survey. Most of it is far shallower: the survey charts 8 closed depth contours over about 91 acres, and half of that water sits inside the 40 ft line. The 88 ft figure is a single recorded sounding rather than a closed contour, so the deepest line you can actually trace on the map is 80 ft.
Where is the deepest part of South Lake?: The deepest charted water on South Lake lies inside the 80 ft contour, toward the southwestern corner of the lake. That contour encloses 1 acres, 1.1% of the mapped water, so it is a small target on a small water, the depth chart above gives the contour to line up on.
How much of South Lake is shallower than 40 feet?: About half. The 40 ft contour encloses 34 acres of the roughly 91 acres inside the outer 5 ft line, so the other half of the water is shallower than 40 feet. The sharpest drop is between 30 and 40 feet, where the mapped water sheds 25 acres.
How accurate is this South Lake depth map?: The contours come from the Michigan DNR Inland Lake Contours survey, retrieved August 2026 and last rebuilt on August 19, 2026. Depths change over time with water levels and sediment, so treat this map as a planning guide for fishing, and never use it for navigation. Acreages are computed from the published contour geometry, not from a separate area survey, so read them as close approximations.

Depth maps for lakes near South Lake

Bruin Lake depth map · 48 ft max · 2 mi away
Halfmoon Lake depth map · 87 ft max · 3 mi away
Pickerel Lake depth map · 56 ft max · 4 mi away
Silver Lake depth map · 47+ ft max · 6 mi away
Portage Lake depth map · 40+ ft max · 10 mi away

Mapped fishing venues near South Lake

South Lake in the venue directory covers access and fishing details for this water.

Bruin Lake · 2 mi away
Halfmoon Lake · 3 mi away
Pickerel Lake · 4 mi away

Fishing in Michigan needs a state license: Michigan fishing license guide · all Michigan venues