Largest Lakes in Iowa

50 Iowa lakes with measured surface area, ranked by acreage. The biggest lake in Iowa is Rathbun Lake, which tops the list at 11,013 acres in Appanoose County.

Lakes with area data

11,013

Largest (acres)

200

Median of top 50

50/50

Reservoirs (vs natural)

Reading Iowa's size profile

Iowa's largest lake by surface area is Rathbun Lake in Appanoose County, spanning 11,013 acres. Most of Iowa's biggest waters are reservoirs — dammed river valleys built for water supply, flood control, and recreation, so their footprints shift with pool level.

Surface area is a poor proxy for water quality on its own — a large lake can hold a clean, deep core and a nutrient-loaded bay at the same time. Each lake below links to its full report card with grade, clarity, depth, and EPA impairment status. Area figures come from state DNR surveys and the USACE National Inventory of Dams; grades come from EPA and state monitoring data.

The 50 biggest lakes in Iowa by surface area

#	Lake	County	Surface area	Max depth	Grade
1	Rathbun Lake	Appanoose	11,013 acres	-	D
2	Lake Macbride	Johnson	950 acres	-	D
3	Black Hawk Lake	Sac	920 acres	-	F
4	Big Creek Lake	Polk	885 acres	-	F
5	Three Mile Lake	Union	880 acres	-	D
6	Little River Lake	Decatur	787 acres	-	F
7	Lake Icaria	Adams	700 acres	-	F
8	Brushy Creek Lake	Webster	690 acres	-	F
9	Lake of the Hills	Scott	657 acres	-	C
10	Rock Creek Max Depth Lake	Jasper	640 acres	-	F
11	Twelve Mile Lake	Union	633 acres	-	F
12	Lake Sugema	Van Buren	574 acres	-	F
13	Pleasant Creek Lake	Linn	410 acres	-	D
14	Lost Grove Lake	Scott	350 acres	-	C
15	Green Valley Lake	Union	336 acres	-	F
16	West Lake Osceola	Clarke	306 acres	-	D
17	Lake Darling Max Depth	Washington	304 acres	-	F
18	Roberts Creek Lake	Marion	296 acres	-	F
19	Center Lake	Dickinson	287 acres	-	F
20	Lake Wapello	Davis	287 acres	-	C
21	Badger Creek Max Depth Lake	Madison	276 acres	-	F
22	Lake Belva Deer	Keokuk	247 acres	-	F
23	Dale Maffitt Reservoir	Dallas	230 acres	-	B
24	Easter Lake	Polk	218 acres	-	D
25	Summit Lake	Union	202 acres	-	F
26	Prairie Rose Lake	Shelby	200 acres	-	F
27	Lake Geode	Des Moines	195 acres	-	F
28	Big Hollow Lake	Des Moines	178 acres	-	F
29	Lake Anita	Cass	171 acres	-	F
30	Hawthorn Lake	Mahaska	160 acres	-	D
31	Don Williams Lake	Boone	160 acres	-	F
32	Morris Lake	Lucas	155 acres	-	F
33	Viking Lake	Montgomery	148 acres	-	F
34	Lake Miami Max Depth	Monroe	140 acres	-	F
35	Volga Lake	Fayette	135 acres	-	F
36	Swan Lake Max Depth	Carroll	130 acres	-	F
37	Beeds Lake	Franklin	130 acres	-	F
38	Lake of Three Fires Max Depth	Taylor	125 acres	-	F
39	Union Grove Lake	Tama	117 acres	-	F
40	Cedar Lake	Linn	115 acres	-	F
41	Lake Ahquabi	Warren	113 acres	-	F
42	Arrowhead Lake	Sac	110 acres	-	C
43	Upper Pine Lake	Hardin	110 acres	-	F
44	Hickory Grove Lake	Story	107 acres	-	D
45	Bob White Lake	Wayne	104 acres	-	D
46	Diamond Lake	Poweshiek	93 acres	-	F
47	Red Haw Lake	Lucas	93 acres	-	F
48	Lake Iowa	Iowa	92 acres	-	F
49	Lake Fisher	Davis	87 acres	-	F
50	Lower Pine Lake	Hardin	85 acres	-	F

Frequently Asked Questions

What is the largest lake in Iowa?

The largest lake in Iowa in the LakeGrade dataset is Rathbun Lake in Appanoose County at 11,013 acres. Water quality grade: D.

How is lake surface area measured?

Surface area comes from state DNR lake surveys and, for reservoirs, US Army Corps of Engineers (USACE) National Inventory of Dams records. Area is reported in acres at normal pool level. Reservoirs rise and fall with management and drought, so their listed area is the long-term normal rather than a single-day reading.

Are Iowa's largest lakes natural or reservoirs?

Of the top 50 Iowa lakes by area, 50 sit on a dammed river (reservoirs) and 0 are natural basins. Glacial states (MN, WI, MI, NY) skew natural; plains and southern states (MO, IA, ND, OH) skew toward reservoirs built for water supply, flood control, and recreation.

Do larger lakes have better water quality?

Not reliably. Quality varies more within a big lake than between lakes — a large lake can have a clean, deep main basin and a murky, algae-prone bay fed by a tributary, so one grade can mask wide swings. Depth, watershed land use, and how fast the lake flushes matter far more than raw surface area.

How big is the typical Iowa lake in this ranking?

Across the top 50 Iowa lakes by surface area, the median is 200 acres (Prairie Rose Lake). This list is biased toward the biggest waters; the typical Iowa lake is far smaller.

Where to stay near Iowa's largest lakes

Planning a trip? Jump to live cabin, resort, and hotel availability near Iowa's biggest lakes.

Deepest lakes in Iowa →Cleanest lakes in Iowa →Largest lakes (all states) →All Iowa lakes →