Financing biodiversity conservation through water tariffs: Naturebased Solutions for the Middle Brenta River Area (North-Eastern Italy)

Biodiversity loss and ecosystem degradation require new financing mechanisms for conservation and restoration. This report examines the middle Brenta River area in North-Eastern Italy, where Nature-based Solutions (NbS) are assessed as a way to finance biodiversity restoration and related co-benefits through water tariffs.

The area supplies drinking water to about 1.5 million people and overlaps with the Natura 2000 site “Grave e Zone umide della Brenta” (IT3260018). Despite its ecological importance, it is affected by intensive agriculture, groundwater depletion, habitat fragmentation, gravel mining, recreational pressure, and fragmented governance.

Five NbS scenarios are compared with a baseline scenario representing current land-use conditions. The interventions include conservation agriculture, constructed wetlands, and forest infiltration areas, implemented either individually or in blended configurations. Their performance is evaluated using three ecosystem service indicators: water infiltration, carbon sequestration, and habitat quality, together with a cost-effectiveness assessment.

Results show that forest infiltration areas provide the highest groundwater recharge and carbon sequestration, while constructed wetlands deliver the greatest habitat-quality improvement. Blended NbS scenarios achieve the most balanced overall performance by combining multiple benefits at moderate cost. The study therefore supports establishing an environmental fund financed through water tariffs to channel resources into biodiversity conservation and ecosystem restoration.