Buying or Selling on Canyon Lake? What You Need to Know About Flowage Easements and the 948 Line

Buying a waterfront home on Canyon Lake is one of the most exciting opportunities in Central Texas real estate. The lake is beautiful, the Hill Country setting is hard to beat, and waterfront property here continues to be one of the most sought-after lifestyle purchases in our market.

But like many Corps of Engineers lakes, Canyon Lake has a few important rules that buyers and sellers need to understand before making decisions near the shoreline.

This is not meant to scare anyone away from buying on Canyon Lake. Quite the opposite. When you understand the basics of government-owned land, flowage easements, surveys, and the 948 line, you can move forward with much more confidence.

The key is simple: know what you own, know what you can use, and ask the right questions before you buy, sell, build, or alter anything near the lake.

For a helpful official reference, you can review the U.S. Army Corps of Engineers guide here: Know Your Boundaries at Canyon Lake .

What Is a Flowage Easement?

A flowage easement is private property where the federal government has retained certain rights related to flood control and reservoir operations.

In simple terms, you may own the land, but the U.S. Army Corps of Engineers has the legal right to occasionally flood, overflow, or submerge that land as part of Canyon Lake’s flood control purpose.

Around Canyon Lake, flowage easement land is generally associated with land below the 948-foot elevation contour. This is why you will often hear people refer to “the 948 line.”

However, this is where things can get a little tricky. Not every property’s easement automatically follows the 948 contour exactly. In some cases, the actual easement may be based on deed history, metes and bounds, or recorded documents. That means buyers and sellers should not rely on assumptions alone.

A good survey, title review, and, when needed, a conversation with the Corps can make all the difference.

Fee Property vs. Flowage Easement: Why the Difference Matters

One of the most important distinctions around Canyon Lake is the difference between government-owned fee property and privately owned land with a flowage easement.

These are not the same thing.

Government-Owned Fee Property

Government-owned fee property is public land owned by the federal government and managed by the Corps of Engineers. Around Canyon Lake, this typically includes land near the shoreline and the area around the normal conservation pool.

This land must generally remain in its natural state. On government-owned property, private owners typically cannot build structures, store personal property, operate motorized vehicles, clear vegetation, mow, or create private improvements without proper written authorization.

That means no patios, decks, stairs, fire pits, private cart paths, lawn furniture, kayaks, trailers, ATVs, golf carts, or shoreline landscaping should be placed on Corps-owned public land unless the Corps specifically allows it.

A common misunderstanding is that if the land is behind your home, you can use it like your backyard. That is not always true. Even if your home is adjacent to Corps land, that land may still be public land. Adjacent owners usually have the same pedestrian access rights as the general public, but not private exclusive use.

Flowage Easement Land

Flowage easement land is different. This is still privately owned land, but it comes with restrictions because the Corps has flood control rights.

On flowage easement land, owners may be able to mow, clear, plant vegetation, use the property recreationally, and construct certain permeable fences without written consent, as long as those activities do not interfere with the government’s easement rights or alter the grade.

However, many structures and improvements require written consent from the Corps before work begins.

That distinction matters a lot in a real estate transaction. A structure located on fee property may need to be removed. A structure located within the flowage easement may be allowed if it has proper written consent and does not interfere with flood storage or violate habitation restrictions.

What Is the 948 Line?

The 948 line generally refers to the 948-foot elevation contour around Canyon Lake. This line is important because it often represents the upper extent of the flowage easement. In other words, it helps identify where Corps restrictions may apply on privately owned land.

But there are two versions of the “948 line” that buyers and sellers need to understand.

The Plat Line

Many older plats or surveys show a simplified straight line labeled as the 948 contour or 948 line. This may be a general reference pulled from an older subdivision plat.

It is helpful, but it may not be precise.

The Actual Contour Line

The actual 948 contour line follows the real elevation of the land. It is usually curved, winding, and based on the property’s topography.

This is the line that matters most when evaluating whether a structure may be inside the flowage easement.

For sellers, this means an old survey with a straight 948 line may not be enough.

For buyers, this means you should not assume a patio, deck, pool, outdoor kitchen, or other improvement is compliant simply because it appears to be above a line on an older survey.

The best practice is to have a current survey that shows the actual 948 contour line, and if a structure is close to that line, an elevation certificate may also be recommended.

What Can Be Built in a Flowage Easement?

The good news is that a flowage easement does not mean you cannot use your property.

In many cases, improvements may be allowed with written consent from the Corps.

Examples of projects that may require written consent include swimming pools, storage sheds, pole barns, patios, decks, gazebos, fire pits, septic or sewer-related improvements, water intake lines, and certain utility-related work.

The big conditions are:

• The structure cannot be for human habitation.
• The project cannot reduce flood storage capacity.
• Written consent must be obtained before work begins.

That last point is important. No work should begin before consent is completed and signed by all parties.

If material is added below the 948 line, the Corps may require an equal or greater amount of material to be removed so there is no net loss of flood storage capacity.

For example, if a project adds concrete, stone, or fill material below the 948 line, the owner may need to show exactly how much material is being added and where material will be removed to offset it.

This is why volume calculations, engineered drawings, and detailed plans may be required.

What Is Strictly Prohibited?

The biggest prohibited category is structures for human habitation.

That includes permanent or temporary structures intended for people to live in, sleep in, or occupy as lodging.

Examples can include houses, additions, guest quarters, tiny homes, RVs, fifth wheels, pop-up campers, tents, yurts, and other temporary or portable overnight lodging structures.

Commercial buildings are also generally prohibited within the flowage easement.

Another major rule: structures should not be attached to a habitable structure if they extend into the flowage easement in a way that makes them an extension of the home.

This can matter with decks, porches, and similar improvements near the 948 line.

There is also a common misconception that if the footings of a deck or structure are outside the 948 line, it can cantilever over the line. That is not something buyers or sellers should assume.

If a structure crosses into the restricted area, even overhead, it may still be an issue.

Why Do These Rules Exist?

At first glance, some of these rules can feel frustrating. But they are not random.

Canyon Lake was created for flood control, water supply, recreation, and public benefit. The land and easement system around the lake helps preserve flood storage capacity and allows the reservoir to function as intended during major rain events.

If too many structures, retaining walls, patios, pools, fill, or other improvements are placed inside the flood storage area without review, the lake’s flood storage capacity can be reduced.

That does not just affect one owner. It can affect neighboring properties, downstream communities, and the overall operation of the lake.

The rules are also designed to protect property owners from investing in improvements that may be damaged or destroyed by high water.

So the goal is not to make Canyon Lake harder to enjoy. The goal is to protect the lake, protect homeowners, and preserve the flood control system that makes Canyon Lake work.

The Current Owner Is Responsible

This may be the most important point for buyers.

If you buy a property with an existing violation, the responsibility generally follows the property.

In other words, if a previous owner built something without proper consent, the current owner may be the one responsible for correcting it.

That can feel unfair, but it is one reason due diligence matters so much.

A simple way to think about it is this: if you buy a car with illegal window tint, you may be the one who gets the ticket, not the person who sold you the car.

The same concept can apply to unauthorized structures or improvements near Corps property or within a flowage easement.

This is why buyers should ask questions before closing, and why sellers should be proactive before listing.

What Sellers Should Do Before Listing

If you are thinking about selling a Canyon Lake waterfront property, the best thing you can do is get ahead of potential issues.

Do not wait for the buyer, lender, title company, surveyor, or Corps to discover a problem late in the transaction.

1. Review Your Existing Survey

Look for the Corps boundary, flowage easement references, the 948 line, and any improvements near the shoreline.

If your survey only shows a straight plat line, it may be worth asking a surveyor whether the actual 948 contour line should be added.

2. Locate Written Corps Consents

If you have improvements below the 948 line, try to locate any written consents or approvals from the Corps.

This may apply to pools, patios, sheds, walkways, septic systems, water intake lines, or other improvements.

If you cannot find the documents, contact the Corps office and ask if they have records.

3. Consider a Pre-Sale Survey

A pre-sale survey can help identify potential issues before a buyer is involved.

That gives you time to solve problems on your timeline instead of under contract deadlines.

4. Disclose What You Know

Full disclosure is one of the best protections a seller has.

If you know about a Corps issue, encroachment, missing consent, cease and desist letter, or unpermitted improvement, disclose it properly.

Trying to hide a problem can create much bigger issues later.

5. Provide the Corps’ Know Your Boundaries Guide

For Canyon Lake waterfront listings, it is smart to provide the Corps’ Know Your Boundaries at Canyon Lake guide as part of the disclosure package.

This helps buyers understand the rules early and creates a more transparent transaction.

What Buyers Should Do Before Closing

Buying on Canyon Lake can be a fantastic decision, but buyers should go in with eyes open.

Before your option period expires, here are some important steps to consider.

1. Read the Survey Carefully

Do not just check whether the house sits inside the boundary lines.

Look for Corps boundary lines, flowage easement references, the 948 line, encroachments, improvements near the lake, and structures such as decks, pools, patios, walkways, or retaining walls below or near 948.

2. Ask About Written Consents

If there are improvements in the flowage easement, ask whether the seller has written consent from the Corps.

Do not assume approval exists just because the improvement has been there for years.

3. Understand What Title Insurance Does and Does Not Cover

Title insurance is important, but it does not automatically insure zoning compliance, land use compliance, Corps compliance, or whether every improvement was properly permitted.

If a title company adds an exception related to an encroachment or easement issue, that may protect the title company more than it protects you.

4. Ask Questions Early

Your leverage is strongest before closing.

If there is a concern, you may be able to ask the seller to provide written consent, correct the issue, remove the unauthorized improvement, or negotiate price or terms to account for the risk.

Once you close, the issue may become yours to handle.

Septic Systems Can Be Especially Important

Septic systems near Canyon Lake deserve special attention.

Proposed sewer line and septic system installations generally require prior approval from the appropriate city, county, or state health departments. Septic system installations may also need to meet specific distance and elevation requirements.

This can matter a lot for older homes and smaller waterfront lots.

Some older septic systems may have been approved under older rules. But if a system needs to be replaced, expanded, or reconfigured, current rules may apply.

That is something buyers should investigate during due diligence, especially if the home is older or the lot is steep, narrow, or close to the lake.

A Helpful Q&A Point from Hagan Cohle

During the Q&A portion of a recent Corps-related presentation, Hagan Cohle with The Lakefront Group asked several practical questions that many buyers and Realtors are probably wondering but may not know to ask.

One of the biggest topics was old septic approvals and old Corps consents.

The answer was encouraging but cautious: sometimes those records can be found. Property owners should check their own records, public records, the county clerk, and the Corps office. The Corps may also be able to search internal records or district office records.

But records can be missing.

That is why it is so important for sellers to keep these documents and for buyers to request them before closing.

This Should Not Scare Buyers Away

Canyon Lake remains one of the best waterfront and water-view markets in Central Texas.

Flowage easements and Corps boundaries are not reasons to avoid buying here. They are simply part of understanding the property.

The buyers who get into trouble are usually not the ones who ask too many questions. They are the ones who assume.

They assume the patio is legal because it looks nice. They assume the prior owner got permission. They assume title insurance covers everything. They assume the straight line on an old survey tells the full story. They assume they can drive a golf cart or ATV anywhere between the house and the lake.

Those assumptions can be expensive.

But with the right team, most of these issues can be identified early and handled correctly.

Final Takeaway

If you are buying or selling on Canyon Lake, the goal is not to be fearful. The goal is to be informed.

Before you build, dig, clear, alter, buy, or sell near the shoreline, make sure you understand:

• Where the government-owned fee property begins
• Whether your private land is subject to a flowage easement
• Where the actual 948 contour line is located
• Whether existing improvements have written Corps consent
• Whether your survey is detailed enough
• Whether any septic, water intake, or utility improvements need further review

Waterfront property is special, and Canyon Lake is no exception.

The more you understand before closing, the better you can protect your investment and enjoy the lake with confidence.

At The Lakefront Group, this is exactly why we focus so heavily on waterfront-specific due diligence. Canyon Lake property is not the same as buying a standard subdivision home, and working with agents who understand the lake, the shoreline, the Corps issues, and the transaction process can make a major difference.

Whether you are buying, selling, or just trying to understand what you own, the best advice is simple:

Ask before you assume.

And when in doubt, get the survey, call the Corps, and work with people who understand Canyon Lake waterfront property.

Note: This article is intended for general educational purposes only and should not be considered legal, engineering, surveying, title, or permitting advice. Always verify property-specific questions with the appropriate professionals and the U.S. Army Corps of Engineers.