The aim of the project is to establish a nature-based stormwater management system—a surface-flow constructed wetland—along the Niidu Ditch in Võru, on the cadastral units at F. R. Kreutzwaldi Street 85a and 85b. The solution is part of the city’s stormwater drainage system, designed to slow down surface runoff, reduce flood-risk areas, and purify stormwater before it reaches Lake Tamula.

The total area of the planned wetland is approximately 2.3 hectares, with a length of about 120 meters and a width ranging from 14 to 30 meters. The depth varies between 0.1 and 0.7 meters, depending on the water level. The wetland consists of a shallow water channel, terraced slopes, sedimentation basins, and embankments with footpaths designed as a recreational area.

Stormwater is planned to be directed into the wetland through the existing Niidu Ditch and the Jüri Street pipeline. Before reaching the wetland, the water passes through a sedimentation basin, where larger suspended solids and sediments are removed. The wetland functions as a retention pond, where stormwater is naturally purified through vegetation and sedimentation processes. This solution helps reduce the pollutant load entering Lake Tamula and enhances biodiversity.

In designing the project, calculations were based on a 20-minute rainfall event with a 100-year recurrence interval, under which the wetland can buffer up to 1,680 m³ of stormwater. Geological studies indicated that the groundwater level is about 0.5 meters deep and the soil infiltration capacity is low; therefore, infiltration was not planned.

The wetland will be equipped with two monitoring wells and two moisture sensors, enabling automatic monitoring of water quality and soil moisture. A solar-powered data transmission and power supply system will be installed at the monitoring wells.

This nature-based wetland will help the city of Võru implement climate change adaptation (LATESTadapt) principles, improve stormwater quality, and provide residents with an attractive green area network.

The construction works are scheduled for 2026.

Review the construction project documentation via the links below:

Explanatory memorandum for the construction project

Site Plan of the Construction Project