Nutrient runoff into U.S. streams and rivers continues to be a serious issue.
Sometimes matters reach crisis level, as they did last summer in Toledo, when 400,000 residents were blocked from drinking the city’s water due to a toxic algae bloom in Lake Erie, largely due to runoff from crops and livestock operations. Or consider the Chesapeake Bay watershed, which remains under heightened scrutiny amid a blend of pollution solutions that include forest buffers, conservation tillage, stormwater practices, urban nutrient management and composite urban practices.
But according to a recent report from the USDA Economic Research Service (ERS), restoring and protecting wetlands, especially in productive corn-producing areas of Illinois, Indiana and Ohio, could be a cost-effective nutrient runoff solution.
ERS estimates that agriculture currently contributes around 60% to 80% of the total nitrogen and 49% to 60% of the total phosphorous that ends up in the Gulf of Mexico. ERS analysis found that annually, wetland restoration or preservation costs between $0.03 and $5.00 per pound of nitrogen removed. Other findings include:
- Wetlands on farmland are not likely to provide significant flood protection unless they are in close proximity to urban areas.
- Wetlands in the upper Mississippi and Ohio River watersheds are capable of removing up to 1,800 lbs of nitrogen per acre from water leaving farm fields.
- The effect of new wetlands on greenhouse gas concentrations is valued between $0 and $129 per acre in the areas studied.
- While some wetlands are able to recharge groundwater supplies, the majority do not. This is because some wetlands are fed by groundwater, while others have impermeable subsoil.
To-date, the USDA has invested more than $4.2 billion toward wetland restoration and protection.