A Burnet County septic permit starts with LCRA's address map

Distance from the water is only part of the septic answer. LCRA's OSSF area reaches about 2,200 feet around the upper Highland Lakes and 2,000 feet around Lake Travis. It also serves certain city limits. A mailing address or lake view cannot settle the boundary.

Enter the address in LCRA's jurisdiction map before installing, changing, or repairing a septic system. If the point falls near a line, the map tells you to call. Inside LCRA's area, follow its permit path.

Outside LCRA jurisdiction, Burnet County generally handles the OSSF review. Start with the map, then carry the parcel and project to the office it identifies. That is safer than measuring from the shore by eye.