Drainage and Your Neighbor: Texas Water Code 11.086 Explained

You build a patio, add a French drain, or raise the back corner of the yard. Then your neighbor knocks and says water is now running into their garage. Or it happens the other way around: you watch a new fence, a pile of fill dirt, or a fresh slab next door push water into your yard.

Texas has a statute that speaks to this exact situation. It is Texas Water Code section 11.086. This post explains in plain English what it says, how courts have read it, and how to avoid trouble. We are drainage contractors and not lawyers, so this is general information and not legal advice. If you have a dispute, talk to a Texas attorney.

What the statute says

Section 11.086 of the Texas Water Code deals with the “overflow of diffused surface water.” In everyday terms, it makes it unlawful for a person to divert or impound the natural flow of surface water in a way that damages the property of another person by flooding it.

A person whose property is injured by an overflow caused by that kind of diversion or impoundment has remedies “at law and in equity.” That means they can sue for money damages and can ask a court for an order, such as an injunction. The statute does not, on its own, say who pays for the fix. A court decides that based on the facts.

The statute also says it does not affect certain flood-control improvements, like levees, or canals built to carry irrigation or other authorized water. In other words, it is aimed at ordinary landowners changing the flow of rain runoff, not at public flood-control projects.

You can read the current text on the Texas Statutes website. Laws change, and several bills in past sessions have proposed adding criminal penalties for some violations. Check the current version instead of relying on our summary.

What counts as “diffused surface water”?

Diffused surface water is rainwater or snowmelt that spreads across the ground without following a defined channel. Think of runoff sheeting across a lawn after a storm. It has not yet gathered into a creek or ditch.

Water that runs in a defined creek, stream, or bed is treated differently under Texas law. Water from a sewer line or a leaking pipe is also a different legal topic. If your issue involves a creek like Gilleland Creek or Brushy Creek, floodplain rules and local ordinances come into play too.

The basic elements

Courts have described a claim under section 11.086 as having three parts:

A diversion or impoundment of surface water,
That causes,
Damage to the plaintiff’s property.

Each part matters. A neighbor cannot win simply because water is moving. Someone must have changed the flow in a way that caused harm.

Diversion

A diversion is anything that changes where the water goes. Common examples include:

Raising a lot with fill dirt so water runs off onto an adjacent lot
Installing a wall, fence, or berm that redirects runoff
Building a patio or driveway that sends water toward a property line
Cutting a trench or pipe that carries water onto another yard

Impoundment

Impounding means holding water back. For example, building a barrier that dams runoff so it backs up onto a neighbor’s land.

Damage

Damage is harm to the neighbor’s property, such as flooded buildings, eroded soil, killed landscaping, or foundation problems. The details of proof and the amount of damages are things attorneys and courts work out.

What the law does not do

It helps to be clear about what the statute does not say.

It does not give you the right to be free from all runoff. Water naturally flows downhill, and a lower lot generally receives some water from higher ones.
It does not make every drainage project illegal. Most good drainage work reduces problems, not creates them.
It does not replace local ordinances, deed restrictions, or HOA rules. Your city may have grading, drainage, and permit requirements, and your HOA may add approval steps. Rules vary by city. Check with your city or HOA instead of assuming.
It does not settle every legal question around the phrase “surface water.” Courts have debated its edges, so outcomes can depend on the facts.

Practical examples

Here are a few typical situations and how the statute’s logic might apply. These are illustrations and not legal predictions.

Example 1. New patio. A homeowner pours a large patio that used to be lawn. The patio is pitched toward the back fence, and now storm runoff pours over the fence into the neighbor’s yard where it used to soak in. The neighbor may argue that the patio diverted or concentrated surface water in a way that causes damage.

Example 2. Fill dirt. A homeowner raises a back yard by a foot to level it. Water that used to cross the lot now flows along the new edge and into the neighbor’s low area. That is the kind of grading change that disputes tend to center on.

Example 3. French drain with a bad outlet. A homeowner installs a French drain and ends the pipe at the property line. In heavy rain the pipe delivers a stream of water onto the next yard. Even though the drain helped the installer, the outlet may create the harm.

Example 4. Ordinary runoff. A neighbor’s yard sits lower than yours, and water drains onto it after storms as it always has, with no change you made. That is typically not a diversion by you.

How to protect yourself when you do drainage work

Whether you hire a contractor or do the work yourself, a few habits help.

Take before photos. Record the natural flow of water across your lot, ideally in a storm. Date-stamped video is useful.
Keep the outlet on your own land. Aim discharge toward the street, a recognized swale, or an easement your city approves, not at a neighbor’s yard.
Spread concentrated flow. If water must exit near a property line, use a splash pad or a level spreader so it leaves as a sheet and not a jet.
Maintain the natural direction of drainage. Preserve existing swales and low paths. Do not fill them in without a plan for where the water will go instead.
Check approvals. Your city and HOA may require permits or review for grading and drainage work. Easements often have special rules. See HOA drainage rules in Texas.
Call 811. Utilities run through many easements and property lines. Texas requires notice at least two business days before digging, excluding weekends and holidays. See call 811 before digging in Texas.
Tell your neighbor. A friendly heads-up before work starts prevents many conflicts.

If a neighbor’s work is hurting you

If you think a neighbor’s project has caused water to flood your yard, here is a calm way to approach it.

Document everything. Photos and videos from before and after, with dates. Note the time, rainfall, and where water enters.
Understand your own drainage. Make sure your downspouts, grading, and drains are not part of the problem. Our post on why your yard floods after rain lists common causes.
Talk to the neighbor. Many people have no idea their project changed anything. Offer to show them the footage.
Check city and HOA channels. Your city may have a code compliance or drainage department. An HOA may have an architectural review process.
Get a professional opinion. A civil engineer or a drainage contractor can describe how water moves across the properties. We can help with the drainage side of that conversation, but we are not engineers of record for legal disputes.
Talk to a lawyer. A Texas real estate or property attorney can explain your options, including demand letters, mediation, or filing a claim.

Keep emotions out of the notes. Facts are what matter if the conversation moves to a formal setting.

If a neighbor says your work is the problem

You can use the same steps. Do not ignore the complaint. Look at the data. If your new patio or grading did redirect runoff, a small fix may solve it. Options include:

Re-pitching a patio edge
Adding a swale or catch basin on your side
Moving a downspout outlet
Installing a French drain with a legal outlet
Using a buried line to carry water to the street

Early action costs less than a long dispute.

Where drainage work can fix a shared problem

A lot of conflicts come from water that has nowhere to go. Giving it a path off both lots can help everyone. For example, a swale along a shared line, a catch basin that ties into a street inlet, or a buried downspout line to the curb can reduce the water crossing the boundary. You can read how we approach this in our yard drainage and regrading service page, and see the pipe options on catch basins and channel drains.

Our post on French drain vs surface drain helps you pick between the main tools.

Texas clay makes it more sensitive

In the clay soils east of I-35, such as the Blackland Prairie belt around Pflugerville, Manor, and Hutto, water absorbs slowly. A small change in grade can send a surprising amount of water along the surface instead of into the ground. That makes grading changes more noticeable to neighbors than they would be in sandy soil. The lower the permeability, the more the shape of the land matters.

Lots near creeks, such as those along Gilleland Creek in Pflugerville, may also sit within floodplain or setback rules that apply to filling and grading. Check with the city before moving soil in or near a creek corridor.

A note on easements

Many Texas subdivisions have drainage easements along rear or side lot lines. They are reserved areas where water is meant to flow. Building a fence, shed, or planting bed in the easement can block the flow, and some easements are owned or managed by the city or the HOA. If you want to alter or build in one, check with your city or HOA first.

What this article is not

This is an overview. It does not cover:

Floodplain and creek regulations
Water from broken pipes or sewer lines
Commercial developments
Insurance claims
How a court would apply the law to your facts

Those topics need an attorney or a licensed professional engineer, depending on the question.

Local context

In Pflugerville, neighborhoods with small lots and shared back fences are the places where disputes show up most often, because two or three yards may share a single path for runoff. In Manor, growth on former farmland has changed how water flows across the landscape, and builders’ drainage plans matter.

Next step

If your yard is sending water where it should not, or taking water it should not, a clear plan helps. Request a free estimate and we will look at the flow paths on your lot and explain drainage options that keep the water on a lawful route. For a legal dispute, please consult a Texas attorney.