[smearth]

A variable is the water temperature and it’s oxygenation level.

Shading the feeder waterways with 20 m belts of trees, using carbon credits to offset the establishment costs then compensating farmers for the lost area should help.

Everyone is winning. The higher oxygenated cooler water will utilise nitrogen and phosphate more effectively, less nitrogen and phosphate will get into the water as it’s absorbed by trees and less fertiliser will be required because soil hydrology will improve, reducing the amount that runs off instead of turning into plants.

Every 2km of waterway bank planted would hold 1500 tonne of carbon eventually. Erosion would decrease so some local bridge and road infrastructure budgets could go towards more planting. And everywhere you saw corridors of trees in paddocks you would think of native animals traisping along their natural highways.

Humans won’t cooperate and go backwards financially and or reputationally. This would potentially avoid that. It’s not the optimum but would have a positive impact for all involved and a chance of success.