An inundation easement on Lake Travis is a fancy way of saying that certain parts of private land around the lake can be temporarily flooded during extreme water events. This isn’t a permanent flood zone, but rather a space that the Lower Colorado River Authority (LCRA) can use if Lake Travis rises to unusually high levels—up to 722 feet above mean sea level. Think of it as a flood buffer zone for the LCRA to manage the water safely when there’s too much rain and the lake needs to store more water than usual.
Why Is It Important?
This easement is crucial for flood control around Lake Travis. It ensures that, during extreme weather conditions, the LCRA has the right to use land around the lake to hold back water and prevent flooding in other areas. Without this kind of easement, managing massive inflows of water, especially during heavy rains or storms, would be much more difficult, leading to greater risk for properties and infrastructure downstream. Essentially, the LCRA is going to do everything in its power to not flood Austin.
Can You Build Over an Inundation Easement?
Technically, the land is still privately owned, so you might think, “Hey, why not build there?” Well, it’s not that simple. Building over an inundation easement is risky, and most local building codes won’t allow it. Structures built within this easement could be flooded during extreme weather, and it’s unlikely you’d get the necessary permits to build anything permanent, like a house or a commercial building. Temporary or removable structures might be allowed, but even those come with restrictions. It’s best to check with local authorities before planning anything. You can get approval to build up, as long as your structures bottom inhabitable floor is above the 722 line. If you go beyond the line, you need approval from the LCRA, and whatever you take out, you need to put back in either on your land or some place else. Meaning, any dirt you take out to build, you need to replace on your property, or another partnering property.
What Would Need to Happen at the Dam for It to Flood to the 722 Line?
For the water level in Lake Travis to rise to 722 feet, a few things would have to align. Normally, the lake is managed to stay well below that level, around 681 feet on average. But during massive rain events, the lake can rise significantly, especially if the water flowing in exceeds the amount that can be safely released from Mansfield Dam.
If Lake Travis were to reach the 722-foot level, it would likely mean unprecedented rainfall and inflows that overwhelm the dam’s floodgates. It would also mean, that the water has crested 8 ft. over the Dam. The LCRA would manage the situation by releasing water downstream through controlled releases, but if the rain kept coming, the water would eventually spill into the areas covered by the inundation easement.
The last time we had a major flood, was in 1913. The flood occurred as part of a series of significant weather events across Texas that year, including severe flooding along the Brazos River. In Austin, the Colorado River flooded heavily, causing widespread damage throughout the city.
The Colorado River’s floods were particularly devastating at the time, in part because the infrastructure for flood control, such as dams, was either inadequate or non-existent. It was these kinds of events that later spurred significant flood control measures, including the construction of the Mansfield Dam, which now helps manage water levels in Lake Travis and protect the city from similar flooding events
In short, reaching the 722 line is a last-resort scenario and would mean the lake is at its absolute maximum capacity. This kind of event is rare, but the easement is there to protect the surrounding community by giving the LCRA a bit of extra room to work with when needed.
So, while it’s your land, that easement gives Mother Nature (via the LCRA) the upper hand when the lake levels rise!
