The San Antonio River level for one mile from West Nueva Street to South Alamo Street has been temporarily lowered by 3.5 feet, officials said Wednesday.

City officials said this has been done to accommodate the San Antonio Water System's water and sewer infrastructure upgrades currently being installed near the Blue Star art complex on South Alamo Street.

VIEW: Map of San Antonio River water level changes

The infrastructure being upgraded in the area, including sewer lines constructed of brick, dates back to 1925.

Dropping the river level temporarily is a precautionary measure. It will relieve pressure on underground bridge piers and flood gate supports. The pipe being replaced runs 50 feet below the river.

Officials said pipe replacement under the river should be completed within 30 days, allowing the river level to return to normal.

The city of San Antonio and SAWS are coordinating with the San Antonio River Authority to implement a marine and wildlife management plan established by SARA. This will ensure minimal impact to marine and wildlife species while the work is done, authorities said.

The utility work being performed by SAWS is in coordination with the city's drainage-improvements project on South Alamo Street from Probandt Street to Pereida Street.

Officials said city infrastructure upgrades will alleviate drainage problems, improve roadway conditions and enhance pedestrian access to the area. Utility improvements for this project are being completed by SAWS, AT&T and CPS Energy.

The overall project, costing $6.1 million, is scheduled for completion in August 2014, city officials said.