How deep is Mashapaug Lake?

Mashapaug Lake reaches a maximum depth of 35 feet in the CT DEEP Lake Bathymetry survey. Most of it is far shallower: the survey charts 8 closed depth contours over about 288 acres, and half of that water sits inside the 20 ft line.

Where is the deepest part of Mashapaug Lake?

The deepest charted water on Mashapaug Lake lies inside the 35 ft contour, toward the southern end of the lake. That contour encloses 14 acres, 4.9% 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 Mashapaug Lake is shallower than 20 feet?

About half. The 20 ft contour encloses 115 acres of the roughly 288 acres inside the outer 0 ft line, so the other half of the water is shallower than 20 feet. The sharpest drop is between 10 and 15 feet, where the mapped water sheds 76 acres.

How accurate is this Mashapaug Lake depth map?

The contours come from the CT DEEP Lake Bathymetry 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.

Connecticut lake depth maps

Mashapaug Lake depth map

Mashapaug Lake in Union, Connecticut reaches a depth of 35 feet. Mashapaug Lake is charted here across 8 closed depth contours, from the 0 ft line down to 35 ft, enclosing about 288 acres of water. Half of that water lies inside the 20 ft line, and only 14 acres lie inside the deepest one. Every contour is on the interactive map below, free and without an account.

Data: CT DEEP Lake Bathymetry (CC0). Contours closed, checked and area-computed by Jordan Carter, founder of GilledIt · page updated August 19, 2026

Mashapaug Lake depth chart: 8 depth contours from 0 to 35 ft

Data: CT DEEP Lake Bathymetry (CC0), retrieved August 2026 · depths change over time · not for navigation

Mashapaug Lake depth chart data: water enclosed by each contour
Depth contour	Water inside it	Share of mapped water
0 ft	288 acres	100%
5 ft	263 acres	91%
10 ft	229 acres	79%
15 ft	153 acres	53%
20 ft	115 acres	40%
25 ft	76 acres	26%
30 ft	33 acres	12%
35 ft	14 acres	4.9%

Acreages are computed from the closed CT DEEP Lake Bathymetry contour rings, with islands subtracted. Shares are of the 288 acres inside the outermost charted contour (the 0 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.

Fishing Mashapaug Lake: steep sides for its size

Inside its outermost 0 ft contour the survey charts about 288 acres of Mashapaug Lake, with the 20 ft line enclosing half of it, so the bottom holds its depth well out from the bank rather than tapering off a long shallow margin. The sharpest change on the chart is between 10 and 15 ft, where the mapped water loses 76 acres in 5 ft of depth, that band is the contour to work first, because it is where the bottom stops being flat. 14 acres, 4.9% of the mapped water, lie inside the deepest 35 ft contour, toward the southern end of the lake. With 35 ft at its deepest there is no true cold-water layer here, so structure does the work the thermocline does elsewhere: fish the points and inside turns where the 10 and 15 ft lines pinch together, hardest in early season and again as fish follow bait back down in autumn.

Ice fishing on Mashapaug Lake

Mashapaug Lake's 35 ft is a workable ice depth, enough water to hold fish all winter, without the slow freeze-up of a big basin. First light belongs on the 35 ft hole, all 14 acres of it; as the sun gets up, move onto the 10–15 ft break, and spend the middle of the day on the flats inside the 20 ft line. Check ice thickness locally before you walk out.

Mashapaug Lake depth map FAQs

How deep is Mashapaug Lake?: Mashapaug Lake reaches a maximum depth of 35 feet in the CT DEEP Lake Bathymetry survey. Most of it is far shallower: the survey charts 8 closed depth contours over about 288 acres, and half of that water sits inside the 20 ft line.
Where is the deepest part of Mashapaug Lake?: The deepest charted water on Mashapaug Lake lies inside the 35 ft contour, toward the southern end of the lake. That contour encloses 14 acres, 4.9% 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 Mashapaug Lake is shallower than 20 feet?: About half. The 20 ft contour encloses 115 acres of the roughly 288 acres inside the outer 0 ft line, so the other half of the water is shallower than 20 feet. The sharpest drop is between 10 and 15 feet, where the mapped water sheds 76 acres.
How accurate is this Mashapaug Lake depth map?: The contours come from the CT DEEP Lake Bathymetry 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 Mashapaug Lake

Bigelow Pond depth map · 15 ft max · 2 mi away
Black Pond depth map · 21 ft max · 5 mi away
Roseland Lake depth map · 18 ft max · 10 mi away
West Thompson Reservoir depth map · 30 ft max · 12 mi away
Crystal Lake depth map · 42 ft max · 14 mi away

Mapped fishing venues near Mashapaug Lake

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

Bigelow Pond · 2 mi away
Black Pond · 5 mi away
Quasset lake · 10 mi away

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