Building in the Lake Travis Floodplain

If you are considering building on Lake Travis andabove 690 four times since 1990. As the lake has
probably on many other lakes, there are some thingsnever been higher than 711 feet, placing these at 715
you need to know. Lake Travis is west of downtownfeet or higher would probably fine, but there would still
Austin, Texas around 45 minutes. Everything in thisbe some risk.
article will be specific to Lake Travis, but it may provideMany of the available lots you will find with frontage on
some things to think about for anyone building on anyLake Travis will not have public water or sewer. Septic
lake.systems are quite common. There are two types you
The first thing a buyer of Lake Travis waterfrontcan install. If there is sufficient room, a gravity system
property needs to learn about is the floodplain. The fullcan be used. These septic systems have next to
level of Lake Travis is 681 feet above sea level. Thenothing mechanically so they are less susceptible to
floodplain is at 722 feet. Why the huge difference?damage by flood waters. Aerobic septic systems
Lake Travis rises and falls depending on rain and onhave many mechanical parts. Aerobic systems are
water use. Lake Travis is the main flood control lakegenerally installed when there is less room for a large
of the Highland Lakes and it is managed by the Lowerunderground septic drain field.
Colorado River Authority (LCRA). The LCRA hasHere is the problem with a septic system: when the
obligations to release water downstream because oflake floods, the septic tank cannot function properly. If it
water contracts. At times without rain, the lake willis an aerobic system, the electricity will not be working
drop. When we get too much rain, the LCRA holds itand the equipment will not work. If it is a gravity
back in Lake Travis to minimize or preventsystem, the tank won't be able to drain. In other words,
downstream flooding.when the lake floods and your system is under water,
OK, so the level of Lake Travis can change. Whatyou can't count on using plumbing. This may be fine if
does that have to do with building on lakefrontyou have a weekend house, but what about living
property? With the floodplain at 722 feet, thethere full time. When Lake Travis floods, the water
requirement for building is that the first occupied floorusually is back down in a week or so, but even being
of a house needs to be at 723 feet or higher. So theunable to use a house for a week may be a problem.
first thing you need to know is the elevation of the lot -The LCRA has specific rules about locations of septic
the whole lot - and the location of the floodplain if partsystems. The basic rule is that the lowest point of the
of the lot is in it. Most lots on Lake Travis slope andseptic drain field must be at the elevation of 691 feet
the slope can be gentle or it can be very steep. If theor higher. In some cases a holding tank might be lower
lot is low to begin with, you probably want to build asthan this, but the effluent would need to be pumped to
close to toe highest level of the lot as possible.a higher drain field and this would require a variance
Some lots are obviously very much in the floodplain.from the LCRA. So once again, you need to know the
Many of the houses will be built on stilts. Some leaveelevation of the entire lot in order to know if a septic
the area under the house open. The builder of othersystem can even be installed.
houses enclose large garages under much of theRegarding water, if the lot you are looking at does not
house with brick or stone.have some sort of municipal water supply, you will
Many of these houses will have multiple flights of stairs.need a well or to draw water out of the lake. The
Others will install ramps. You may be wondering aboutLCRA does allow pumping water from Lake Travis
an elevator instead of stairs or a ramp. My thought isfor household use and landscaping, but you need a
that this is just one more mechanical system that willcontract with the LCRA to do that. You will also need
be damaged when the water rises and an elevatora holding tank and purification equipment. All of this
would probably be pretty expensive to replace orshould also be placed at a high enough elevation so
repair.none of the equipment is within easy reach of
Other things to think about that get more detailed arefloodwaters.
the septic system, the location of air conditioningSo getting back to building on a Lake Travis
compressor, a propane tank if you will have gas, thewaterfront lot, there are things you need to know
electrical service panel (breaker box) and waterbefore going out and looking at lots. If you work with a
system equipment if not on city or other private water.Lake Travis REALTOR®, he or she should be able
To minimize damage, these items should be elevated.to provide guidance in these areas.
Lake Travis has been above 700 feet three times and