^^carp^^

there is about 10 square feet in walnut

None of the above... fluctuating water levels killed off a bunch of it. Lake was 4ft or more over pool for a few months during the prime growing season, then dropped to regular pool level. That killed off a TON of the shallower grass that was growing. I found some wads of deeper grass, like 15 ft or so, in February that are still there going strong but the hydrilla we were ripping traps in back in January is long gone.

Same thing happened to Rayburn and Toledo, notorious grass lakes. Water fluctuations have killed most of the grass.