Not legal advice. This page explains the rules in plain English, each linked to the law or ordinance it comes from. For a dispute over real money or property, talk to a lawyer; the State Bar of Wisconsin's Lawyer Referral Service is (800) 362-9082.
The Reasonable Use Rule
- Wisconsin's rule since 1974. In State v. Deetz the Wisconsin Supreme Court adopted the "reasonable use" rule for surface water (rain and snowmelt running over land), replacing the old "common enemy" rule.(State v. Deetz, 66 Wis. 2d 1) Under the old rule, an owner could deal with surface water any way they liked, whatever it did to the neighbors.(State v. Deetz)
- What it means: each owner can make reasonable use of their land even if that changes the flow of surface water and causes some harm, but is liable when the harmful interference is unreasonable.(State v. Deetz)
- How a court weighs it: harm is unreasonable when its seriousness outweighs the usefulness of what the neighbor did, or when it's substantial and paying for it wouldn't make the project unworkable. Once a neighbor knows they're causing harm and keeps going, it counts as intentional.(State v. Deetz)
- Doing nothing isn't unreasonable. In Hocking v. City of Dodgeville (2009), storm water ran from uphill lots onto the homeowners below. The uphill owners weren't liable, because they hadn't done anything to change the flow.(Hocking v. City of Dodgeville, 2009 WI 70) A duty to act comes from using your property unreasonably.(Hocking v. City of Dodgeville)
So a claim needs something the neighbor did, like regrading, adding fill, paving, or aiming a downspout or sump line, that changed the flow and caused unreasonable harm. Water that has always run downhill across the lots usually isn't anyone's fault.
What to Do
- Document it. Photos and video during a rain, dates, and any damage. Note what changed and when (a new patio, regrading, a new sump line).
- Talk to the neighbor. Often it's a downspout or sump line that can be turned. Madison's own guidance asks owners to aim sump discharge so it doesn't go straight onto the neighbor's property.(City of Madison)
- Check the town rule. Every town below bans sending sump water into the sanitary sewer, and several limit where it can go. A violation is something the town can act on.
- Call the town. In Madison, Engineering and Building Inspection both handle sump discharge problems.(City of Madison) Erosion and flooding go to Engineering.(City of Madison)
- Fix your own side. Madison suggests fixing grading, gutters and downspouts first, and draining a sump somewhere that doesn't slope back to the house.(City of Madison)
Sump Pumps in Madison
- Never the sanitary sewer. Madison bars connecting foundation drains to the sanitary sewer,(MGO 35.02) and storm water, groundwater and roof water can't go into it without City Engineer and MMSD approval.(MGO 35.02) A basement floor drain is part of the sanitary system, so it's out too.(City of Madison)
- Where it can go: onto your own property, straight into the storm sewer if one is close (usually within 100 feet), to the curb under the sidewalk, or into an infiltration bed on your lot.(City of Madison)
- A pipe through the curb needs a permit, because the curb and gutter are part of the storm system.(MGO 37.05) The application fee is $100, with no surcharge for a sump flowing up to 100 gallons a minute.(MGO 37.05)
- Pumps that run all year should go to the storm sewer if possible; on a yard or curb they make moss and algae in summer and ice in winter.(City of Madison)(City of Madison)
- If the City knows of a problem discharge, it may extend the storm sewer and have Building Inspection order the owner to connect. That can take about a year.(City of Madison)
Sump and Downspout Rules by Town
Where sump and roof water may go, from each town's code.
| Town | Sump and downspout rule (code section linked) |
|---|---|
| Madison | No sump, roof or groundwater into the sanitary sewer; no downspouts onto sidewalks; curb outlets need a permit(MGO 35.02(5)(a)3; MGO 10.29; MGO 37.05(7)(a)1; MGO 27.05(2)(y)) |
| Cottage Grove | Footing-drain and crawl-space pump water may go to the storm sewer; other non-stormwater discharges are banned(§ 164-5A(2)(e)) |
| DeForest | No sump or roof water into the sanitary sewer; use storm sewer, dry well, or ground without causing a nuisance(DeForest Code § 14.23(2)–(4)) |
| Fitchburg | No groundwater, roof runoff or other clear water into the sanitary sewer without approval(Fitchburg Code § 40-685(a)) |
| Maple Bluff | Not found. We couldn't find this rule in the town's code; ask the town. |
| McFarland | No sump pump or downspout water into the sanitary sewer; downspouts may not drain onto the public sidewalk(McFarland Code § 8-306, § 8-307, § 8-308, § 53-70) |
| Middleton | Downspouts, foundation drains and groundwater may not connect to the sanitary sewer(Middleton Code 9.05(5)(e)) |
| Monona | Downspouts may not discharge onto or drain over the public sidewalk(§ 395-9) |
| Mount Horeb | Not found. We couldn't find this rule in the town's code; ask the town. |
| Oregon | No sump, roof or groundwater into the sanitary sewer, except Nov 15–Apr 1 with written OK from Public Works(Oregon Code § 13.28(2)(a)) |
| Shorewood Hills | Storm or surface water may not connect to the sanitary sewer; footing-drain pumps may go to the storm sewer(Shorewood Hills Code § 14.04(1), § 26.05(1)(b)(v)) |
| Stoughton | No sump, roof or foundation water into the sanitary sewer; do not divert stormwater toward neighbors(Stoughton Code §§ 10-93, 74-89(h), 10-317(c)(1)) |
| Sun Prairie | No sump water into the sanitary sewer, across sidewalks Nov 15-Apr 15, or onto neighbors if it does damage(Sun Prairie Code § 15.04.120(C); § 12.36.040) |
| Verona | No sump or roof water into the sanitary sewer; discharge to storm sewer, dry well or ground without nuisance(Verona Code § 15-1-13(a)-(d)) |
| Waunakee | No sump or roof water into the sanitary sewer; downspouts may not drain onto public sidewalks(Waunakee Code § 105-91; § 58-5) |
Erosion and Grading
- Madison bans letting soil erode, or tracking or dropping dirt, onto neighboring land, streets or water from any property, permit or not.(MGO 37.07) An erosion control permit is needed for disturbing more than 4,000 square feet or moving more than 400 cubic yards of soil.(MGO 37.06)
- Driveway culverts and roadside ditches are the adjacent owner's to keep clear in Madison; the City can clear one that's causing overflow damage.(MGO 37.05)
- Madison Engineering: 608-266-4751, engineering@cityofmadison.com. Its report-a-problem form has categories for erosion control and flooding.(City of Madison)
- In the towns (unincorporated areas), Dane County Land and Water Resources issues erosion control permits on similar thresholds; 608-224-3730.(Dane County)(Dane County)
Basement water from the ground up is a different problem; flooding and lake levels covers floodplain maps and flood insurance.
Questions
Is my neighbor responsible for water running onto my property in Wisconsin?
Only if they did something unreasonable. Wisconsin follows the reasonable use rule: each owner can use their land even if it changes how surface water flows, but is liable when the harm is unreasonable. Water that just runs downhill naturally isn't the uphill neighbor's legal fault.
Where can I drain my sump pump in Madison?
Onto your own property, into the storm sewer if one is close, to the curb under the sidewalk, or into an infiltration bed. Never into a floor drain or the sanitary sewer. A pipe through the curb needs a City permit.
Who do I call about drainage problems in Madison?
City Engineering at 608-266-4751 for erosion, flooding and storm sewer problems, and Building Inspection at 608-266-4551 for a problem on a neighbor's property.