Indiana drainage laws start from a single idea: surface water that runs across the ground without a defined channel is a “common enemy,” and any landowner may fend it off, redirect it, or speed it along, as long as they don’t gather it up and dump it on a neighbor. Everything else — regulated drains, floodway permits, wetland rules, easements, assessments — layers on top of that baseline, and which layers apply depends on where the water goes and what you plan to build.
The Common Enemy Doctrine
Under the common enemy doctrine, diffuse surface water is a shared problem every landowner can address as they see fit. You can wall it out, grade to shed it, speed its flow, or build structures that change where it goes. The Indiana Court of Appeals reaffirmed the rule in N.G. Hatton Trust v. Young (2018), noting that a landowner may deal with surface water “in such a manner as best suits his own convenience.”
The limit is concentration. Grading your yard so rainwater sheets faster across your neighbor’s lawn is generally lawful. Building a berm that pools water and channels it through a single opening onto the neighbor’s driveway is not. The doctrine protects you when you accelerate natural flow. It does not protect you when you create an artificial, concentrated discharge.
When Surface Water Becomes a Watercourse
The doctrine only covers diffuse surface water. Once water enters a creek, stream, or established drainage channel, riparian rules take over. Downstream owners along a natural watercourse have enforceable rights to continued flow, and upstream owners cannot make changes that substantially increase flooding downstream. Many drainage disputes begin right at this line, because a soggy low spot to one owner may qualify as an intermittent stream under the law.
Regulated Drains and the County Drainage Board
Every Indiana county has a drainage board that oversees “regulated drains” — open ditches, underground tile lines, or a combination of the two. Boards operate under IC 36-9-27 and can order improvements, classify drains, assess costs to benefiting landowners, and enforce compliance when someone interferes with the system.
The county surveyor classifies every regulated drain under IC 36-9-27-34 into one of three categories: drains needing reconstruction, drains needing periodic maintenance, or drains that should be vacated. Reconstruction may mean converting an open ditch to tile, enlarging tile, deepening or widening a channel, or building detention basins. Periodic maintenance covers cleaning, spraying, obstruction removal, and minor repairs.
Landowners can push for a different classification. If at least ten percent of the property owners affected by a particular drain petition the board to classify or reclassify it, the board must hold a public hearing after notifying all affected owners. That is the mechanism to use when a neglected drain needs reconstruction or an expensive drain should be vacated.
Permits You May Need Before You Dig
IDNR Floodway Construction Permit
The Indiana Department of Natural Resources requires a floodway construction permit for any project that builds, excavates, or places an obstruction in a floodway. The minimum nonrefundable fee is $200, and the application requires plans, specifications, and proof of ownership or written authorization. IDNR issues the permit only if the project won’t reduce floodway capacity, create an unreasonable safety hazard, or cause detrimental effects on fish, wildlife, or plant resources.
Not every project near a waterway triggers the requirement. Reconstruction or maintenance of a regulated drain on a stream or open drain totaling ten miles or less in length is exempt, as is certain highway bridge construction in rural areas over streams with upstream drainage areas of fifty square miles or less.
IDEM Construction Stormwater General Permit
The Indiana Department of Environmental Management administers the Construction Stormwater General Permit (CSGP), which replaced the older Rule 5 program in December 2021. Any construction that disturbs one acre or more requires CSGP coverage. Projects disturbing less than an acre still need the permit if they’re part of a larger common plan of development. The application is filed online, requires a Stormwater Pollution Prevention Plan (SWP3), and costs $175.
County Drainage Board Approval
Under IC 36-9-27-17, landowners must get approval from the county drainage board before modifying any regulated drain. That includes connecting private tile to a regulated drain, deepening or rerouting a legal ditch, or installing new tile that feeds the regulated system. This approval is separate from any IDNR or IDEM permit and focuses on protecting the capacity of the county’s drainage infrastructure. Skipping it can lead to mandatory project modifications, fines, stop-work orders, or court injunctions.
Federal Section 404 and Wetlands
Drainage work that discharges dredged or fill material into waters of the United States, including wetlands, requires authorization from the U.S. Army Corps of Engineers under Section 404 of the Clean Water Act. Covered activities include filling for construction, building dams or levees, installing riprap, creating ponds, laying subaqueous utility lines, and even temporary fills for access roads during construction.
The scope narrowed after the U.S. Supreme Court’s 2023 decision in Sackett v. Environmental Protection Agency, which held that only wetlands with a “continuous surface connection” to traditionally navigable waters qualify for federal protection. Isolated wetlands and those separated by dry land generally fall outside federal jurisdiction.
Agriculture gets meaningful exemptions. Normal farming on established cropland, including minor drainage work, doesn’t require a Section 404 permit. Maintenance of existing drainage ditches and construction or maintenance of farm ponds and irrigation ditches are also exempt. Constructing new drainage ditches in waters of the United States is not exempt, and bringing previously unfarmed land into production through drainage work doesn’t qualify as an established operation.
State Wetland Tile Rule
Under IC 13-18-22-4, maintaining field tile in a Class II wetland requires a state general permit, but only if the tile is necessary to restore drainage of adjacent land and doesn’t drain the wetland itself. Tile maintenance in a Class I wetland doesn’t require a state permit.
Drainage Easements and Right of Entry
County drainage boards have a statutory right of entry near regulated drains. Under IC 36-9-27-33, the county surveyor, the drainage board, or their authorized representatives can enter land within 75 feet of any regulated drain for inspection and maintenance. The 75-foot distance is measured at right angles from the center line of a tiled drain or the top edge of each bank of an open drain.
That distance isn’t fixed. For regulated drains established after September 1, 1984, and for urban drains, the board can reduce the right-of-way to as little as 25 feet from the top of each bank of an open ditch, or 15 feet from the center line of a tiled drain. In platted subdivisions, the board can go lower for tiled drains, but never below seven feet from each side of the center line. Reductions require a recommendation from the county surveyor.
Property owners within a drainage right-of-way cannot place structures or carry out activities that interfere with flow or block maintenance access. Beyond the statutory right-of-way, drainage easements can also arise from written agreements, recorded plats, or long-standing use. Indiana recognizes prescriptive easements for drainage after 20 years of actual, open, continuous, and uninterrupted adverse use. If a neighboring property’s drainage has crossed your land openly for two decades without objection, the neighbor may have acquired a legal right to continue that pattern.
Maintenance Costs and Assessments
Maintenance of regulated drains is the drainage board’s responsibility, funded by assessments on landowners who benefit from the system. The board oversees dredging, debris clearing, and repairs. Costs are spread among benefiting owners, and refusing to pay your share can result in a lien on your property.
IC 36-9-27-43 caps assessment accumulation. If a drain’s maintenance fund has an unencumbered balance of four times or more the estimated annual maintenance cost, the annual assessment can be skipped for the year. The board can still collect above the four-times threshold after a public hearing, but assessments must stop entirely once the fund would reach eight times the estimated annual cost.
If you believe an assessment is unfair, file written objections with the board. After a public hearing, the board may modify it. You then have 20 days after the board publishes its decision to request judicial review. Miss that window and the order becomes final.
Private drainage systems outside the regulated network are entirely the landowner’s responsibility. If your private tile or ditch fails and causes water damage to a neighbor, you can face civil liability for nuisance or negligence. The common enemy doctrine won’t protect you when the harm comes from a failed drainage system you were responsible for maintaining, as opposed to natural surface flow.
Enforcement and Lawsuits
County drainage boards have primary enforcement authority over regulated drains. If you obstruct a legal drain, alter water flow without approval, or build within the right-of-way, the board can issue compliance orders and hire contractors to fix the problem at your expense. For neighbor-to-neighbor disputes over drainage changes, the process typically starts with the board, which can hold hearings and order corrective action.
When the board process doesn’t resolve the issue, or when the dispute involves purely private drainage systems, affected owners can sue. Common claims are nuisance (the drainage change unreasonably interferes with your property use) and negligence (the other landowner failed to maintain their system). Courts can order injunctive relief forcing restoration of prior drainage patterns, award money damages, or appoint engineers to evaluate and recommend solutions.
For property damage claims tied to drainage system deficiencies, Indiana’s statute of limitations generally runs ten years from the date the improvement was substantially completed, or twelve years from when plans and specifications were submitted to the owner if the claim targets a design defect. Those longer windows apply specifically to claims against designers or possessors of improvements to real property. Standard tort claims for ongoing drainage nuisance follow shorter limitation periods, so acting promptly after you discover damage matters.
Buying or Selling Property with Drainage Concerns
Indiana requires residential sellers to complete and sign a disclosure form and give it to a prospective buyer before an offer is accepted. Drainage problems, flooding history, and known defects in drainage infrastructure fall within the conditions a seller should disclose. Buying a property with undisclosed drainage issues can support claims against the seller, but finding those issues after closing is far more expensive than catching them during due diligence. If the property sits near a regulated drain, check with the county surveyor’s office to learn the drain’s classification, the applicable right-of-way, and any pending reconstruction or assessment plans before you commit.