Where do storm drains run under downtown Austin?

Downtown Austin has about 113 km of mapped storm-drain pipe (8,637 segments), of which about 83 km is active. The network follows the street grid and drains to Waller Creek, Shoal Creek and Lady Bird Lake.

Watershed	Pipe segments	Inlets
Waller Creek (WLR)	3,064	986
Shoal Creek (SHL)	2,604	703
Lady Bird Lake (LBL)	2,449	569
Town Lake (TWN)	496	343
Boggy Creek (BOG)	24	6

• Status: 6,525 pipe segments are active. 1,570 removed, 411 inactive and 131 other records (never built, under construction or due for removal) are still in the data.
• Biggest conduits: the Waller Creek tunnel segments, 270 to 318 inches across, were built in 2010. In total, 449 segments are 60 inches or wider.
• Inlets: 2,607 curb and grate inlets, 1,472 of them active.
• Age: recorded build years run from 1904 to 2025.

How this was worked out

• We used City of Austin storm drain pipes and curb and grate inlets (Watershed Protection Department).
• We clipped them to the City's Downtown planning-area boundary.

Limitation: the map shows every pipe record, including removed and inactive ones.