1. Bathymetry of Lake Travis
Christina Stanard
GIS in Water Resources
Fall 2006

2. Background
Lake Travis is one of the Highland Lakes, which are formed by six dams on the Colorado River.
Lake Travis is a “flood-control” lake which means it is designed to accommodate floodwaters to prevent destruction downstream. It’s neighbors, Lake Marble Falls and Lake Austin, are “constant-level” lakes. Lake Travis has to STORE EXCESS or PROVIDE MORE water so these lakes can remain at constant elevations. This is why the elevation of Lake Travis is ever-changing.
Image courtesy of LCRA

3. Mansfield Dam Lake Travis Lake Austin Elevation when full = 681 ft.
Dam Spillway Elevation = 714 ft.
Current Elevation = ft.
From Lower Colorado River Authority:
Lake Austin
Mansfield Dam was constructed in 1940
It is 266 feet high.
LCRA is reservoir controlling authority.
Image courtesy of Google Earth

4. Purpose
Develop a depth chart of Lake Travis according to the current water level
Include boat launches and attractions
Find the difference in surface area from the change in elevation
Lake Travis is a haven for recreational boating. The combination of boating and changing water depths can be deadly. Lake Travis is the “deadliest” lake in Texas partly due to it’s uneven bottom. (kxan.com)
Boaters in Devil’s Cove on Lake Travis (Image courtesy of

5. Making the Chart Bathymetric data for the lake, converted to depth
the bathymetric data was a text file with x and y coordinates and the corresponding elevation above mean sea level. Edited in EXCEL to convert to depth.
The DEM shows the lake Full at 207 meters (or 681 feet)
Outline of lake acquired from National Hydrography Dataset (NHD)

6. Making the Chart
Adjusted the depth for the current elevation of ft.
2.) in Excel: found depth and then adjusted for the current elevation

7. Chart of Lake Travis and its Attractions
Boat Launches show “open” if the lake elevation is above their minimum operating elevation.
Restaurant locations. Coordinates from Google Earth

8. Zooming in Islands in middle of lake
Restaurants are no longer accessible by boat.

9. Lake Austin and Mansfield Dam
Maximum Lake Travis elevation of 681 Feet, Austin is 492 feet.
Mansfield Dam currently (Travis at 644 ft.) changes the water elevation 152 feet!!
ESRI Satellite Imagery for the background

10. Future Work Changing Shoreline
The surface area of the lake when it is full is 18,929 acres (78 km2)
Interested in finding the area when the lake is at the current elevation...
Using raster calculation

11. Improvements More elevation data points for the Lake
This data is only 2 points/acre
Elevations for boat access to attractions
As shown on the zoomed in slide, the data points are too spread out. 100 meters apart.

12. Questions?