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Have you ever studied Winnipeg Manitoba? They have used artificial levees, diversionary spillways and dredging to alleviate the flooding problems on the red River which flows north through the city. This has always been a problem on the Red since downstream it cools and freezes up while upsteam it may be a warm spring day adding lots of water to the river levels. grand forks is ALWAYS in the news in Springtime with flooding. But Winnipeg seems to have engineered the problems away. In the summer you drive through the city and see on the outskirts these wide shallow diversion canals and wonder at first about their purpose. But come in late spring and they are full of water, doing their job.

Winnipeg could still plant more trees and natural prairie grasses to hold water, too. These are all good tactics to aid in flood prevention. One thing you did not mention is runoff from streets and paved areas. The less paved areas that exist, the more water can soak in and be held by ground. More green spaces mean less flooding.

Another thing that has been done away with in most areas are private cisterns. This used to be common and could also play a big part in curing excess use of water resources. Each home should have a cistern, that is, a holding tank for rainwater falling and running off of their house roofs. They were usually made of brick mortared and waterproofed to hold water runoff for household uses. ideal would be to add a pressure pump that turns on with demand for an outside faucet, flushing toilets and doing laundry. With filters I place to remove and catch debris (leaves and dust) and an overflow pipe for when the cistern is full, this natural soft water eliminates the need for a water softener reducing salts gong into the water supply, would eliminate the need to ration water in hot months for watering gardens and lawns, would hold excess water during times of excessive rains and stop the stupid practice of flushing toilets with drinkable water: a win-win situation for consumers and the environment too.