Removable Steel Stop Log with Rubber Seal

I need a removable stop log to seal a water channel that is 6.5 feet wide and 14 feet deep. I am considering using 5/16" to 3/8" plate with 2" x 6" x .125 tubing spaced x inches and welded to the back horizontally or the width. in between the tubing I would weld 3/8" plate welded vertically spaced x". The channel is concrete and I will have to anchor a 3" x 5" x .375 thick angle to each side and the bottom in order to seat the stop log against. I would propose using 3/4" by 10" chemical concrete anchors, spaced x inches apart.

Requirements:
- Material: Steel
- Seal Type: Rubber seal
- Must be designed for easy removal

Ideal skills & experience:
- Metal fabrication
- Experience with water sealing solutions
- Ability to create removable structures