So much water has already been drawn from the delta that more than 90 per cent of the original wetlands have disappeared, says Yassa.

These ingenious irrigation systems transformed the original wetland into extremely productive land, farmed until the late 1950s.

Less than 10% of the original wetland area remains.

The original wetland was filled in for athletic fields and a new one of equivalent size was excavated and filled with water.

In the mid-20th century, one third of the original bay had been filled, and only ten percent of original wetlands remained.

The island has become largely void of wildlife and vegetation, as 97% of the original wetlands around the Detroit River were depleted by 1982.

Humrickhouse said that solution could be used "only when every alternative for saving the original wetland was exhausted."

But the original wetland underwent drainage for agricultural purposes beginning in 1897, and by the early 1960s all but 60 ha had been drained.

An even larger fraction of the world's original wetlands than of its forests has already been destroyed, damaged, or converted.

Part of the original wetlands were drained and divided among villae rusticae.