Lakes Monitored	Year of map used	Iowa County	Lake Area in acres	Watershed Area in acres (excluding lake surface)	Watershed/Lake Area Ratio	Volume in cubic meters	Mean Depth in meters	Maximum Depth in meters
Big Spirit Lake	1971	Dickinson	4,169	34,603*	8.3	116,135,600	5.3	7.3
Center Lake	1972	Dickinson	272	735	2.7	3,207,519	2.9	4.7
East Okoboji Lake	1970	Dickinson	1,835	12,295	6.7	23,474,520	3.2	6.7
Elk Lake	1991	Clay	261	NC	NC	NC	NC	1.8
Little Spirit Lake	1970	Dickinson	618	1,669	2.7	4,584,987	1.8	3.0
Lower Gar Lake	1972	Dickinson	242	11,374	47.0	1,062,456	1.1	1.7
Lake Minnewashta	1972	Dickinson	118	295	2.5	1,481,000	3.1	5.0
Silver Lake	1971	Dickinson	1041	11,391	10.7	7,784,362	1.8	3.4
Trumbull Lake	1979	Clay	1,190	NC	NC	NC	NC	1.2
Upper Gar Lake	1972	Dickinson	36	439	12.2	150,863	1.0	1.5
West Okoboji Lake	1970	Dickinson	3,847	13,849	3.6	178,578,600	11.5	41.5
NC = not calculated. All data except Elk and Trumbull from Bachmann et al 1980- Note: Bachmann's Big Spirit Lake watershed area includes the Minnesota watershed draining to Loon Lake which in turn drains to Big Spirit Lake*