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2,905-acre lake in Macon County, Illinois. The lake tops out around 28 ft. Contours on this water are modeled from its actual shoreline and max depth. Good for finding likely water, never for navigation. Here's the year, species by species, as the scoring engine sees it.
Lake Decatur maps at 3,020 acres behind 46 miles of shoreline, broken up by 8 islands. An index of 6 puts the bank firmly in maze territory: point after pocket after cove, every one a casting target. The shallow band under 15 ft claims about 89% of the surface on the model — that's where the groceries are. End to end it runs roughly 9.6 mi, about 3.8 mi across. Macon County claims this one. Lake Clinton sits 23 mi north — the closest neighbouring chart.
When the water first warms, bluegill slide up into 1 to 6 ft. Summer is a 4 to 15 ft game here, winter a 10 to 25 ft one. Start at Shallow bay flat. It's a weed flat holding about 3 ft of water and rates prime come spring. The feeding windows run early morning and the evening. Keep a small sponge spider (fly) or a micro tube jig rigged through the warm months.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 1 to 6 ft | midday & dusk | Shallow bay flat (3 ft) | 1/32 oz jig + micro plastic, Tiny popper (evenings) |
| Summer | 4 to 15 ft | dawn & dusk | Weed flat (6 ft) | Small sponge spider (fly), Micro tube jig |
| Fall | 6 to 18 ft | midday | Weed flat (6 ft) | Micro jig + waxworm, Small spoon tipped |
| Winter | 10 to 25 ft | midday | Deep basin (24 ft) | Tungsten ice jig + plastic, Tiny spoon |
When the water first warms, channel catfish slide up into 3 to 12 ft. By summer they slide out to 8 to 25 ft, and by winter most fish are in 8 to 28 ft. If you only fish one area, make it Deep basin: a deep basin around 24 ft that scores prime in winter. In summer the feeding windows fall in after dark and the evening.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 3 to 12 ft | dusk | Feeding flat (8 ft) | |
| Summer | 8 to 25 ft | night & dusk | Deep basin (24 ft) | |
| Fall | 8 to 28 ft | dusk | Deep basin (24 ft) | |
| Winter | 8 to 28 ft | midday | Deep basin (24 ft) |
Early season common carp use the shallows, holding in 2 to 10 ft. Summer is a 3 to 15 ft game here, winter an 8 to 28 ft one. The chart's best answer is Shallow bay flat — weed flat, 3 ft, prime for spring. Best bite is early morning and the evening.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 10 ft | midday & dawn | Shallow bay flat (3 ft) | |
| Summer | 3 to 15 ft | dawn & dusk | Shallow bay flat (3 ft) | |
| Fall | 5 to 18 ft | midday | Weed flat (6 ft) | |
| Winter | 8 to 28 ft | midday | Deep basin (24 ft) |
Come spring, look for crappie tight to the bank in 2 to 8 ft. Expect a summer slide to 10 to 25 ft, then a winter hold in 8 to 28 ft. Start at Deep basin. It's a deep basin holding about 24 ft of water and rates prime come winter. Prime time lands in early morning and the evening. A jig trolled/spider-rigged or a small crankbait (trolled) is the honest summer answer here.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 2 to 8 ft | midday & dawn | Shallow bay flat (3 ft) | 1/16 oz jig + tube, Curly-tail grub |
| Summer | 10 to 25 ft | dawn & dusk | Break off the point (13 ft) | Jig trolled/spider-rigged, Small crankbait (trolled) |
| Fall | 8 to 20 ft | dawn | Break off the point (13 ft) | Jig + minnow combo, Small swimbait (1.5-2") |
| Winter | 8 to 28 ft | midday | Deep basin (24 ft) | Tungsten jig + soft plastic, Tiny jigging spoon |
Come spring, look for flathead catfish tight to the bank in 5 to 20 ft. They move out to 7 to 28 ft in summer and finish the year down in 8 to 28 ft. If you only fish one area, make it Deep basin: a deep basin around 24 ft that scores prime in fall. Best bite is after dark and the evening.
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 20 ft | night & dusk | Deep basin (24 ft) | |
| Summer | 7 to 28 ft | night & dusk | Deep basin (24 ft) | |
| Fall | 8 to 28 ft | night & dusk | Deep basin (24 ft) | |
| Winter | 8 to 28 ft | midday | Deep basin (24 ft) |
Spring freshwater drum on Lake Decatur hold shallow, usually 5 to 20 ft. They move out to 7 to 28 ft in summer and finish the year down in 8 to 28 ft. Put Gravel shoal first on the milk run — a gravel shoal near 5 ft that grades prime for spring. The feeding windows run the evening. The summer box starts with a jig + crawler combo or a small crankbait (slow).
| Season | Depth | Best window | Start at | Go-to baits |
|---|---|---|---|---|
| Spring | 5 to 20 ft | midday & dawn | Gravel shoal (5 ft) | Jig + curly tail (bounced), Small blade bait |
| Summer | 7 to 28 ft | dusk | Break off the point (13 ft) | Jig + crawler combo, Small crankbait (slow) |
| Fall | 8 to 28 ft | midday | Deep basin (24 ft) | Blade bait (vertical), Jigging spoon |
| Winter | 8 to 28 ft | midday | Deep basin (24 ft) | Jigging spoon (slow) |
Lake Decatur also holds largemouth bass (8 to 20 ft in summer), sauger (8 to 28 ft in summer), saugeye (8 to 22 ft in summer), smallmouth bass (8 to 28 ft in summer), striped bass (8 to 28 ft in summer), walleye (8 to 28 ft in summer), white bass (8 to 25 ft in summer), white bass & hybrids (8 to 28 ft in summer). Pick any of them on the map above for rated spots and bait picks.
Structure-wise the chart holds 19 features, led in depth by Deep basin at roughly 24 ft.
Season dates, license requirements, and size and bag limits for Illinois waters are set by the Illinois DNR — and special regulations can apply to Lake Decatur specifically, so confirm the current rules before you fish.
Check the official Illinois fishing regulations →
Lake Decatur is about 28 ft (9 m) deep at its deepest point. The contours here are modeled from the water's real shape and maximum depth, so treat them as a rough guide.
Anglers target bluegill, channel catfish, common carp, crappie, flathead catfish, freshwater drum, largemouth bass, sauger, saugeye, smallmouth bass, striped bass, walleye, white bass, white bass & hybrids on Lake Decatur.
Shallow bay flat is the top-rated area: a weed flat in about 3 ft of water that rates prime for bluegill in spring. The map above holds the full rated-spot list for every species and season.
For bluegill, the summer bite is best in early morning and the evening. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.
Fishing on Lake Decatur is regulated by the Illinois DNR. Check the official Illinois regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.
Lake Clinton 23 mi · Lake Shelbyville 27 mi · Sangamon River 28 mi · Taylorville Lake 32 mi · Lake of the Woods 33 mi · Sangchris Lake 36 mi · Lake Paradise 38 mi · Dawson Lake 39 mi · Lake Mattoon 41 mi · Lake Springfield 41 mi · Walnut Point Lake 46 mi · Charleston Lake 47 mi
See how Lake Decatur stacks up: best largemouth bass lakes in Illinois · best smallmouth bass lakes in Illinois · best walleye lakes in Illinois · best white bass lakes in Illinois
Browse all Illinois fishing maps or see every water on DepthScout. How we build these maps. Fish here with a sonar unit that logs? Send us your depth data and we'll improve this chart, credited to you. For fishing guidance only, never navigation.