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Fishing regulations at Ditch Number 40, IA
Disclaimer: Always check local fishing regulations, water access rights and land ownership before fishing, regardless of any catches logged in that area by the Fishbrain community. Fishbrain has mapped millions of acres of government-owned land across the USA to help you identify potential fishing access, but you are responsible for ensuring compliance with all legal requirements.
Fishing regulations in Iowa can change throughout the year. Make sure to check this page before fishing for the most up to date rules and regulations for the current season. Local regulations govern when you can fish, the max size of the fish you can keep, how many fish you can keep, and more.
Below you will see fishing regulations for catching Smallmouth bass as of April 25th, 2026. To view regulations for a different fish species, please click on your preferred species in the drop-down.
Seasons
Bag limit
Min size
Measurement
Special gear
Aggregate
Statewide regulations: No closed season.
Daily bag limit = 3 bass (largemouth, smallmouth, and spotted bass, combined).
Daily possession limit = 6 bass (combined)
EXCEPTIONS:
All black bass caught from the following stream segments and lakes must be released alive immediately:
- Brown Lake (Jackson)
- Cedar River (Mitchell) extending downstream from the bridge on county road A19 east of Otranto as posted to the bridge on county road T26 south of St. Ansgar
- Maquoketa River (Delaware) extending downstream from below Lake Delhi Dam as posted to the first county gravel road bridge
- Middle Raccoon River (Guthrie) extending downstream from below Lake Panorama Dam as posted to the dam at Redfield
- Upper Iowa River (Winneshiek) extending downstream from the Fifth Street bridge in Decorah as posted to the upper dam
- Wapello Lake (Davis).
Inland Waters:
- Minimum size = 15-inches in all public lakes, including Coralville, Rathbun, Saylorville, and Red Rock reservoirs except as otherwise posted, including:
- Ada Hayden (Story): 18-inch minimum
- Ahquabi, Hooper (Warren): 18-inch minimum
- Big Creek: 18-inch minimum
- Casey (Tama): 18-inch minimum
- Cold Springs (Cass): 18-inch minimum
- Green Valley (Union): 18-inch minimum
- Hawthorn (Mahaska): all 12 to 16-inch fish must be immediately released!
- Hendricks (Howard): 18-inch minimum
- Krumm (Jasper): 18-inch minimum
- Little Wall (Hamilton): 18-inch minimum
- Lost Grove (Scott): 18-inch minimum
- Mill Creek (O'Brien): 18-inch minimum
- Pleasant Creek (Linn): 18-inch minimum
- Smith (Kossuth): 18-inch minimum
- South Prairie (Black Hawk): 18-inch minimum
- Sugema (Van Buren): all 12 to 18-inch fish must be immediately released!
- Swan Lake (Carroll): 16-inch minimum
- Thomas Mitchell: 18-inch minimum
- Yellow Banks (Polk): 18-inch minimum
Interior Streams & River Impoundments
- Minimum size limit = 12-inch minimum except
Boundary Rivers (including associated chutes and backwaters where intermittent or constant flow occur)
- Daily Bag Limit = 5 bass (largemouth, smallmouth, and spotted bass, combined).
- Possession Limit = 10 bass (largemouth, smallmouth, and spotted bass, combined).
- Mississippi River: Minimum size = 14-inches total length.
- Missouri River: Minimum size = 12-inches total length.
Micropterus dolomieui
Regulations for
FAQ about Ditch Number 40 fishing
- Smallmouth bass - 1 members reported to have caught this fish
- @bigrig82mn reported a nice Smallmouth bass.
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