I have been thinking about slightly different idea to artificial ,dig into mud Lauderits channel.

If you could make a long sleeve a meter or two in diameter, made of plastic, long for example 500m. Even something like heavy duty tarpaulin, PVC pip etc.

then filled with water and partly air. Long , big diameter pipe floating on the water then sunk , then to be re-floated and relocated at wish.

Such sleeve should create efficient wave brake.

Advantage is that we could deflate that sleeve a bit and two, relocate, swing to different location , according to the wind.

Ideal place could be shallow already big lake with clear wind ( Lake George, Cootharabe?)

If diameter is bigger then depth, we could just pump water into sleeve and that will anchor under weight on the bottom.

One sleeve along provide just ideal wave brake.

Two sleeves in parallel and we could create even super flat channel with additional wave brake outside.

I guess such artificial speed run could be feasible only as sort of commercial enterprise - somebody has to invest in material , pump the water, relocate and maintenance.

Small fee from user could be effective means to recover costs.

Municipal environment near by also may benefit from dedicated to the speed tourists bringing money to hotels and restaurants .

I guess there is not much technical problem to create such Artificial Speed Run, environmental opposition could be the issue.