Oregon Drainage Law: Rights, Easements, and Permits

Oregon drainage law follows the civil law rule: neighboring landowners must leave natural drainage patterns alone. Lower-lying land has to accept surface water that flows down to it naturally, and the upstream owner cannot make changes that substantially increase the volume or speed of that flow. Break these rules and you can face civil lawsuits from your neighbor, regulatory fines of up to $10,000 per day for unpermitted work in state waters, and, inside an organized drainage district, liens that can lead to foreclosure on your land.

The Civil Law Drainage Doctrine

Oregon does not use the “reasonable use” or “common enemy” rules some other states follow. Under the civil law rule, the natural course of drainage between neighbors has to stay intact. The lower property owner must accept water that naturally flows from above and cannot block it. The upper owner can use and improve the land but cannot alter drainage in ways that substantially increase the water’s speed or volume onto the property below.¹

One feature of this area of law surprises many landowners. The rules governing drainage between neighbors developed entirely through Oregon court decisions. No Oregon Revised Statute directly codifies them.¹ Statutes do cover related topics, including drainage districts (ORS Chapter 547), county-authorized drainage ditches (ORS Chapter 549), and removal-fill permits (ORS Chapter 196). But the core question of what one neighbor owes another about surface water is answered by case law.

What Upstream Owners Can and Cannot Do

If your land is uphill, you can build, grade, and improve. What you cannot do is gather surface water into ditches or artificial channels and release it onto adjacent land in a way that causes damage. The Oregon Supreme Court set out that principle more than a century ago and courts continue to apply it.

Development is a common trigger. Adding driveways, roofs, patios, and other impervious surfaces increases both the volume and the speed of runoff. Intent is not the test. Even if you never meant to harm your neighbor, substantial changes to flow from construction or grading can create liability. In Senn v. Bunick, the Court of Appeals found trespass when a residential subdivision caused increased flood and surface water across a plaintiff’s land, so the doctrine is not reserved for large commercial projects.

Maintenance matters too. A culvert or ditch that worked when it was installed can silt up and redirect water in ways you never planned. If drainage infrastructure you built falls into disrepair and floods or erodes neighboring land, you are on the hook. When drainage crosses a property line, the party who modified the system is generally responsible for upkeep unless a written agreement says otherwise.

What Downstream Owners Can and Cannot Do

If your land is lower, you have the right to receive surface water in its natural flow pattern. You do not have to accept substantially increased water caused by your uphill neighbor’s changes. You also cannot obstruct the natural flow coming down. Fences, retaining walls, and landscaping features that inadvertently dam natural drainage can put you in violation of the same doctrine you might otherwise rely on.

Legal Claims When Drainage Damages Your Property

Three claims come up most often in Oregon drainage disputes. Nuisance covers persistent problems like standing water that makes portions of your land unusable. Trespass covers water physically entering your property through artificial channels or concentrated flow. Negligence covers cases where the upstream owner failed to take reasonable precautions and the resulting harm was foreseeable.

Oregon courts have recognized all three. In Levene v. City of Salem, the Oregon Supreme Court found that a municipality causing an unusual or unreasonable amount of water to be emptied onto lower property committed both trespass and nuisance. Liability attaches to public and private upstream owners alike.

What You Have to Prove

Winning takes more than showing your property gets wet. Oregon courts have found drainage improper only where the acceleration and concentration of water were substantially increased. You need evidence that the upstream changes meaningfully altered the natural flow. Timestamped photographs, drainage surveys, and before-and-after documentation all help. Expert testimony from a civil engineer or hydrologist is common in contested cases.

Filing Deadlines

Under ORS 12.080, an action for trespass, waste, or interference with an interest in real property must be filed within six years. That window covers most drainage damage claims involving injury to land. There is ongoing debate in Oregon about whether some negligence-based drainage claims tied to construction defects fall under a shorter two-year period, so waiting is risky. Delayed claims are also harder to prove.

What a Court Can Order

Affected owners can seek injunctive relief to stop harmful drainage practices, monetary damages for flooding or erosion, and compensation for diminished property value. Injunctive relief is often the point: a court can order an upstream neighbor to restore drainage to its original condition rather than simply pay after the fact.

Drainage Easements

When drainage crosses property lines, easements decide who has the right to direct water where. Express easements are written into recorded deeds. Implied easements arise from the circumstances of a land transaction, typically when a parcel is divided and one portion has no other way to drain. Prescriptive easements come from long-term open and continuous use adverse to the owner’s rights, and in Oregon that period is ten years.² If surface water has drained across a neighbor’s property openly and continuously for at least ten years without permission, a prescriptive easement may exist.

Once an easement is established, the servient owner generally cannot block or alter it unilaterally. If no easement is documented or provable through long-term use, a claimed easement can be challenged.

Sharing Maintenance Costs

ORS 105.175 addresses upkeep when an easement agreement is silent on the point. Each party sharing an easement pays for maintenance in proportion to their use. Frequency of use and the size and weight of vehicles involved are among the relevant factors. Damage caused by one party’s negligence or abnormal use is that party’s sole expense to repair.³

When Neighbors Refuse Access

ORS 549.110 gives you a route when you need to drain your property but neighboring owners will not agree to construction across their land. You can apply to the county court for a right-of-way to build a drainage ditch, levee, or other drainage infrastructure across adjacent land. The same process is available for landowners whose property is injured or threatened by floodwaters from a nearby stream and who need to enlarge or straighten the streambed.²

Drainage Districts

Property inside an Oregon drainage district organized under ORS Chapter 547 carries duties beyond the general civil law doctrine. Drainage districts can assess charges, perform maintenance on your land, and place liens on your property if you do not pay.

The board of supervisors sets an annual assessment covering district expenses, including maintenance, operations, and estimated delinquencies. That assessment is apportioned across all land in the district, and even parcels smaller than one acre are charged as if they were a full acre.⁴

If a drainage channel or flood control structure on your land is clogged or obstructed and you fail to submit a repair plan within ten days of notice, the district board can do the work and bill you. If you do not pay, the district can file a lien with the county clerk. That lien takes priority over everything except taxes. If it remains unpaid for thirty days, the district can file a foreclosure action and your land can be sold to satisfy the debt.⁴ This is one of the sharper consequences in Oregon drainage law, and it catches landowners off guard when they ignore maintenance notices.

Permits Before You Change Drainage

Drainage work that reaches beyond minor grading on your own dry land often requires permits at the local, state, or federal level. The more your project affects waterways or wetlands, the more layers apply.

State Removal-Fill Permits

Oregon’s removal-fill law generally requires a permit from the Department of State Lands (DSL) for projects that add, remove, or move more than 50 cubic yards of material in wetlands or waters. Some protected areas, including streams designated as Essential Salmonid Habitat and Oregon Scenic Waterways, require a permit for any amount of material.⁵ If your drainage project redirects water into a stream, wetland, or floodplain, you likely need one.

Under ORS 196.810, no person may remove material from the beds or banks of Oregon waters, or fill any state waters, without a DSL permit.⁶ Emergency permits can receive verbal approval when immediate threats to public safety or property exist. Fees vary by project type and scope under a five-year schedule DSL adopted effective January 1, 2026.⁷

Federal Section 404 Permits

Section 404 of the Clean Water Act requires a permit from the U.S. Army Corps of Engineers before discharging dredged or fill material into navigable waters, including wetlands.⁸ Maintenance of existing drainage ditches is exempt. Constructing new drainage ditches is not.⁹ Any activity intended to convert waters of the United States to a new use, and that may impair the flow or reduce the reach of those waters, requires a Section 404 permit regardless of other exemptions.

Local Stormwater Permits

Many Oregon cities and counties regulate drainage through zoning laws and stormwater management ordinances. In urban areas, you often need a permit before altering surface water flow when new construction or landscaping affects established drainage. Larger projects with significant impervious surfaces may need a stormwater facility designed by a licensed engineer. Requirements vary widely, so check with your city or county planning department before you break ground.

Fines and Enforcement

Unpermitted removal from or filling of Oregon waters is punishable by a fine of up to $10,000 per day of violation under ORS 196.990.¹⁰ The Oregon Water Resources Department and Department of Environmental Quality can investigate complaints and require landowners to restore altered drainage conditions at their own expense. Local governments may add penalties, including liens on properties that do not correct violations.

Buying or Selling Property in Oregon

Oregon’s seller property disclosure law addresses drainage directly. Under ORS 105.464, sellers must disclose whether there are problems with settling, soil, standing water, or drainage on the property or in the immediate area, whether the property has suffered material damage from floods, and whether the property is in a designated floodplain.¹¹ These disclosures are based on the seller’s actual knowledge at the time.

If you are buying, a “Yes” or “Unknown” response to the drainage question is a cue to investigate before closing. If you are selling, be honest. Failing to disclose known drainage problems can expose you to claims from the buyer after the sale.

Insurance for Drainage-Related Water Damage

Standard homeowner’s insurance policies typically exclude flood damage, which leaves a gap when drainage causes water intrusion. The National Flood Insurance Program covers damage from the unusual and rapid accumulation or runoff of surface waters, so some drainage-related flooding qualifies.¹²

NFIP policies exclude damage from water that backs up through sewers or drains, discharges from a sump pump, or seeps through the property, unless a flood is the proximate cause.¹² If a neighbor’s drainage modifications cause surface water flooding that triggers a sewer backup, NFIP may cover the damage. If the backup happens without a flood event, it will not. Properties in designated floodplains may be required to carry flood insurance, another reason the floodplain answer on a seller disclosure matters.

1
Oregon Department of Transportation. ODOT Hydraulics Manual – Chapter 2 Legal Aspects
2
Oregon State Legislature. Oregon Code 549 – Application to County Court for Authority to Build Drainage Ditch or Levee, or to Widen or Straighten a Stream
3
Oregon State Legislature. Oregon Code 105 – Easement to Be Kept in Repair; Sharing Costs; Agreements
4
Oregon State Legislature. Oregon Revised Statute Chapter 547 – Drainage Districts
5
Oregon Department of State Lands. Removing or Filling Material
6
Oregon State Legislature. Oregon Revised Statute Chapter 196 – Columbia River Gorge; Wetlands; Removal of Material; Fill
7
Oregon Department of State Lands. Oregon Removal-Fill Program Fees 2026-2030
8
Office of the Law Revision Counsel. 33 USC 1344 – Permits for Dredged or Fill Material
9
eCFR. 40 CFR Part 232 – 404 Program Definitions; Exempt Activities Not Requiring 404 Permits
10
Oregon State Legislature. Oregon Code 196 – Penalties for Unpermitted Removal From or Filling of Waters
11
Oregon State Legislature. Oregon Revised Statutes Property Rights and Transactions 105.464
12
Federal Emergency Management Agency. NFIP Flood Insurance Manual