Pre-Solicitation Synopsis - LOCK AND DAM 25 NEW 1, 200 FT LOCK NAVIGATION AND ECOSYSTEM SUSTAINABILITY PROGRAM (NESP)   6

Background
The U.S. Army Corps of Engineers (USACE), St. Louis District, is preparing to solicit bids for the construction of a new 1,200 ft lock chamber at Lock and Dam 25, located approximately 61.5 river miles upstream from St. Louis and 241.5 miles above the mouth of the Ohio River.

This project is part of the Navigation and Ecosystem Sustainability Program (NESP) aimed at enhancing navigation efficiency and ecosystem sustainability.

Work Details
The contract involves the design and construction of a new 1,200-ft-long drilled-shaft founded lock chamber to be built riverward of the existing 600-ft lock chamber.

Key tasks include:
- Construction of a new upstream ported approach wall;
- Construction of a downstream approach wall designed to block flow through the wall;
- Site development features for access routes, staging areas, disposal areas, operations facilities;
- Extension of the existing Intermediate wall by approximately 600-ft;
- Dewatering and unwatering operations for floor construction;
- Modification of the existing filling and emptying system for the current chamber;
- Construction of a new filling and emptying system for the new chamber;
- Demolition of monoliths for connection to existing walls;
- Demolition of the upstream guard wall;
- Dredging for new chamber construction;
- Close coordination with navigation industry stakeholders to assess impacts on navigation during construction.

Period of Performance
The contract will be performed over a period of nine (9) years.

Place of Performance
Winfield, Missouri

Incumbent Analysis (see Incumbents section for more detail)
This opportunity appears to have a confirmed incumbent and/or closely related prior contract activity at Lock and Dam 25, with Massman Construction previously awarded work supporting the new NESP lock. Massman received $17,048,250 for LD25 downstream approach guide cell construction (06/15/25–09/26/26) and also performed LD25 demolition of an existing cell ($2,017,797; 01/20/26–03/31/26), which aligns with the upcoming scope of building new lock chamber components and associated approach/wall modifications. Additionally, Tetra Tech supported NESP LD25 planning/design efforts for the 1,200-ft lock ($2,923,686; 02/07/24–07/20/26), indicating continuity in the overall project development and construction sequencing.