Specifications include, but are not limited to: The fabrication of three stop gates/sluice gates to allow isolation of the culverts for underwater work. The Black Bayou Culverts Structure consists of ten (10) 10 ft. x 10 ft. concrete box culverts under LA highway 384 which are equipped with trash racks and flap gates. Photos of the structure and various components are located in Appendix D. The typical structure operation is free flapping mode with occasional locking of the gates closed to maintain the desired water level within the project area. For structure maintenance which requires underwater work, a group of box culverts are to be isolated using stop gates/sluice gates which will be fabricated through this Contract. Three 10ft 4in. x 12ft 5¼in. aluminum sluice gates are required for this purpose. The gates will typically remain in storage and only require installation when inspection or maintenance is necessary. Each sluice gate will be lowered into a slot provided in the receiving frame adjacent to the trash screen on the upstream side (East Side) of the culvert structure.