The algae is there in response to a flood of nutrients (nitrogen and phosphorus) that wash in. Where from? Everywhere. Lawn fertilizers, geese poop, ag fertilizers, etc. And, Iowa has naturally rich soils. Phosphorus mainly moves when attached to soil particles,so stopping erosion is key here. But, nitrogen can move on its own, so sediment movement is not as important to its transport. Everyone needs to remember they live in a watershed - meaning, what they put on their land/yard/storm sewer is eventually going to reach a waterbody.
Installation of filter strips to allow the water to slow down and drop the sediment load is one way slow he movement of sediment and nutrients to waterways, but there isn't one silver bullet that will fix it. Iowa is a highly modified state, in terms of out natural environment, with something like >96% of the land under private ownership and control. So, just because someone comes up with modifications/ideas on how to clear up our waterbodies, that doesn't mean it will be adopted. Trying to balance the needs and use of all the land in Iowa with our water quality issues is a headache, that I predict, will not be solved in my lifetime.
