Stop the Delta Tunnel Act This bill prohibits the U.S. Army Corps of Engineers (USACE) from issuing a federal permit that would be necessary to build the proposed Delta Conveyance Project in California. Specifically, the USACE may not issue a Section 404 permit (i.e., a permit that allows for the discharge of dredged or fill material into navigable waters) for the project. The USACE published a draft environmental impact statement in December 2022 about the project, which involves constructing new California State Water Project diversion and conveyance facilities in the Sacramento-San Joaquin Delta. The Delta Conveyance Project includes an underground tunnel to deliver water south of the delta.