The issue is that we've screwed with the water systems in the region so much, that when there is a flood event in areas that have had their natural water flows

The issue is that we've screwed with the water systems in the region so much, that when there is a flood event in areas that have had their natural water flows completely altered, nutrients that have built up in the system that would normally 'trickle-release' slowly are instead dumped en mass into our ocean. Don't forget that for 9 months of the year, the ocean water currents draw waters from the southern coast towards the north... reversing during summer (drought), but when the rainy season hits, and washes the stored nutrients out, the currents pull that artificially nutrient-rich waters directly onto the reef. Its a mess of epic proportions, but unfortunately the cotton profits are too damned high.