SEP: Benefits of constructed wetland ecosystem services worth more than double the costs

A new study featured in Science for Environment Policy (SEP) - "Phosphorus removal performance of a large-scale constructed treatment wetland receiving eutrophic lake water.", published in Ecological Engineering, looks at the benefits of  constructed wetland ecosystem services.

The economic benefits of the ecosystem services provided by constructed wetlands far outweigh the costs of maintaining them, the new research has confirmed. Analysis of a wetland that treats the third largest lake in Florida, US, shows that it provides ecosystem services worth $1.79 (€1.64) million per year, against costs of less than half that figure.

Eutrophication, an excess of nutrients within water, has become a significant environmental problem. Nitrogen and phosphorus pollution enters waterways as a result of run-off of agricultural fertilisers, and can be damaging for aquatic wildlife. Wetlands, which filter pollutants from water before they reach lakes, streams and oceans, can mitigate this problem. Although they occur naturally, artificial wetlands can also be constructed, and are now in use all over the world.

This study assessed the effectiveness of a large constructed wetland in the US. The researchers assessed the ability of the marsh flow-way in Florida, which filters Lake Apopka — the third largest lake in the state — to remove phosphorus from lake water.

Using estimates provided by ecological economics, which give monetary value to ecosystem services such as water pollution control, the researchers were able to estimate that the marsh flow-way provides a value of $1.79 (€1.64) million per year, many times greater than its annual running costs.

However, the researchers say that this is a crude estimate, which should be used to give an idea of the benefits of a wetland approach rather than a precise valuation.

As well quantifying costs and performance, the researchers also considered the ecological benefits of the wetland to assess management of the flow-way. The authors recommend that, when assessing system performance, wetland managers use a cost benefit approach that considers ecosystem services. They say this could lead to more effective and more sustainable water resource management.

Read more in the SEP brief.

Original Source:

Dunne, E., Coveney, M., Hoge, V., Conrow, R., Naleway, R., Lowe, E., Battoe, L. & Wang, Y. (2015). Phosphorus removal performance of a large-scale constructed treatment wetland receiving eutrophic lake water. Ecological Engineering 79, pp.132-142. DOI: 10.1016/j.ecoleng.2015.02.003