The protected slot limit on walleyes is 19 to 25 inches, with only one walleye over 25 inches allowed per day. The protected slot limit. No more than one walleye greater than 20 inches in length may be taken per day. Officials with the Iowa Department of Natural Resources say the protected walleye slot limit will change from 19 to 25 inches on Big Spirit Lake. 1, On Jan. These changes will start January 1, All. Iowa Great Lakes, Storm Lake and Clear Lake walleye length limit changes effective January 1, Iowa Department of Natural Resources (DNR) is changing the protected walleye slot limit to. Until the end of December, the current 17 inch to 22 slot size limit. The DNR is proposing a inch minimum length limit on all walleye captured from Rathbun Lake. [HOST] › About DNR › DNR News Releases. Length Limit: A inch minimum length limit applies to Walleye on all pools of the Mississippi River. The daily bag limit will be three walleyes with one walleye over 25 inches. . In addition, you must immediately release alive all. 1, this changes to a slot limit of 19 to 25 inches at Big Spirit, East and West Okoboji, Upper Gar, Minnewashta, Lower Gar and. The Iowa Department of Natural Resources announced changes to the walleye slot limit at Storm Lake that will take effect on Jan. e. The daily bag limit shall be three, with a possession limit of six.