When heavy rain pounded downtown San Antonio on Friday night, the lower level of I-35 did what too many locals have come to expect: it filled with water, shut down lanes and ramps, and turned the evening commute into a slow-motion parking lot. All this while the state has been paying roughly $14,000 a month to rent and run temporary pumps meant to keep that very stretch from flooding.
The rental setup has been in place since last August as a stopgap to keep the lower level of I-35 through downtown from going under. It still was not enough Friday night, when runoff covered the lower lanes and triggered closures that snarled downtown traffic. TxDOT says it has already picked a contractor for a roughly $22 million pump-replacement project, but the full work is not expected to start until early 2027, which means months more of relying on rented equipment as the region moves into another storm season.
Those temporary units are essentially filling in for aging hardware. Inspectors reviewing the pump houses found some equipment, last replaced in the 1990s, "lacked the capacity to handle a two-year storm event," according to News 4 San Antonio. The station reports TxDOT started the rental program in August and has been paying about $14,000 a month to keep the pumps running. Longtime downtown drivers told the I-Team they have seen water reach the tops of passenger cars and semis when the lower level floods.
The storm that swamped the lower lanes also hit the wider area hard. Local coverage documented high water at Salado Creek and the closure of the I-35 north exit at Martin Street, with regional maps showing more than 30 road closures that morning, per MySA. The same system knocked out power for thousands and set off flash-flood warnings across Bexar County. In that context, it does not take much imagination to see how quickly the sunken lanes downtown can become dangerous when drainage gets overwhelmed.
A Stopgap That Is Getting Expensive
On paper, there is plenty of money circling the I-35 corridor. Regional planning documents list roughly $22.5 million tied to improvements in the I-35 area, according to the Alamo Area MPO TIP, while TxDOT's downtown project page outlines about $25.9 million in repairs and upgrades for I-35 and I-10 downtown. Together, those figures show multiple funding streams pointed at fixing the corridor.
Most of that work, however, is geared toward resurfacing and bridge repairs, not a rapid swap-out of the pump units that have repeatedly failed to keep pace with heavier rains. So the rentals keep humming along, month after month, as the long-term fix inches forward.
What Comes Next
The I-Team reports TxDOT selected a contractor in April to install new pumps sized for a 50-year storm event, but the agency now says actual construction will likely begin in early 2027. That timeline keeps the department on the hook for rental bills and dependent on temporary pumping through at least one more rainy season, according to News 4 San Antonio.
TxDOT also told the station that debris from downtown events has contributed to pump blockages, and that crews have scheduled debris removal in an effort to cut down near-term risk. Until the new permanent pumps are installed, though, repeat closures during heavy rain remain firmly on the table.
For now, commuters who use the lower level of I-35 should brace for periodic shutdowns whenever storms roll through while the temporary system stays in place. TxDOT is directing drivers to DriveTexas and its project pages for the latest lane-closure and construction notices. The rental bill may be small compared with full-scale reconstruction, but the gap between the current stopgap and the long-promised permanent fix leaves little wiggle room before the next big storm tests the system again.
