The news release also cites buildups of nutrients as a concern. High levels of nutrients may cause less desirable plant species to dominate the system.
- Land Subsidence. By some estimates, intensive agriculture has reduced the elevation of the current land twenty feet below where it was before human intervention. As a result, any released water would pool rather than flow. In the words of the Corps: “Soil subsidence in the EAA has substantially reduced the hydraulic head that would drive the southward flow of water; hence, velocities and flow rates would be greatly reduced”;
- Water Loss. The flow way would lose a tremendous amount of water to both seepage and evaporation: “By spreading the water over shallower areas (as opposed to reservoirs) and because a marsh habitat would have to be kept hydrated, the evapotranspiration loss could easily be doubled”; and
- No Steady Supply. “Perhaps the most crucial element, water flowing from the lake to the WCAs [Water Conservation Areas] is not present in dry or even normal years!...The only years where water could flow for long duration are wet periods…[and in] those years, the stages in the WCAs are already too high and additional flow from flowways would be damaging, not beneficial.”
HT:RFF Library Blog