DONALDSONVILLE — A two-block stretch of La. 18 near the Donaldsonville historic district will close for more than five months so workers can install steel pipes beneath the highway to carry water from the Mississippi River to Bayou Lafourche. 

The highway will close Monday, Jan. 20, and remain closed until Friday, June 6. A new pumping station is being built to supply additional freshwater to the bayou, combating saltwater intrusion.

The Louisiana Department of Transportation and Development suggests a five-mile detour via La. 3120, La. 70 and La. 2089. The actual closure covers La. 18 between Chetimatches Street and Iberville Street, a distance of about 800 feet.

The Louisiana Coastal Protection and Restoration Authority in 2022 announced a $96 million project to triple a pump station's capacity, saying the work would ultimately protect water systems in towns along Bayou Lafourche.