The study is about the nature-based horizontal levee that serves as flood protection, improves water quality, and as a sea-level rise climate adaptation measure.

Wastewater treatment plants in coastal areas are facing challenges like the removal of nutrients and trace organic contaminants from wastewater, and effects of climate change such as sea-level-rise, frequent and intense storms, and storm surges.

For two years, the researchers conducted the study on a 0.7-hectare experimental horizontal levee in Lorenzo, California constructed to treat a small portion of the secondary effluent from a conventional activated sludge wastewater treatment plant (Cecchetti, Angela, Katherine and David, 2020).

Native wetland plants were planted in the levee and treated effluent from wastewater plants were introduced.

The wetlands reduce storm surges and while providing space for wetland transgression to a higher elevation as sea levels rise.

The traditional approaches involve the construction of seawalls and levees which is costly.

A horizontal levee is a new and cost-effective approach to do away with raising existing levees as sea-level rises while at the same time reducing contaminants from municipal wastewater facilities.

Nature-based horizontal levees come with multiple benefits as a climate adaptation strategy and wastewater treatment option. It is cheaper to construct than traditional coastal levees and can hold high contaminant mass loads.

To read the complete study, click the link below:

Source citation:

Cecchetti, Aidan & Perantoni, Angela & Graham, Katherine & Sedlak, David. (2020). The horizontal Levee: A multi-benefit nature-based treatment system that improves water quality and protects coastal levees from the effects of sea level rise. Water Research X. 7. 100052. 10.1016/j.wroa.2020.100052.