Estonian cities must prepare for heavier downpours, researcher says

Estonian cities are not yet ready for heavier rain and should plan how to manage stormwater, hydroinformatics researcher Ottar Tamm said, according to ERR.

Tamm, a junior professor of hydroinformatics at the Estonian University of Life Sciences and head of its hydroclimate research group, said Estonia must prepare for rainfall heavier than the downpour that flooded parts of Pärnu in early September. Historical data show that rainfall is already more intense and the climate more variable, he said.

Two months of drought followed by 150 millimetres of rain could still produce a two-month average of 75 millimetres, Tamm said. Cities need to decide where the water will go and begin planning, including by creating digital models to map its flow. He said cities with more paved than green space should have flood-management plans, and street renovations should take account of water flow and possible changes to the road’s profile or height.

Tamm also said residents should be told if their homes are on a water flow path or in a high-risk flood zone, and advised to prepare for flooding, including by getting a pump and making a plan.

On September 4, Pärnu recorded 122.4 millimetres of rain, breaking a rainfall record that had stood for 150 years. Flooding inundated gardens and homes in the Rääma district. Pärnu Deputy Mayor Sander Kilk said the city knew about flood-prone areas in the seaside district but was caught by surprise in Rääma, where water flowed from the nearby Rääma bog.

The Rescue Board was also unprepared and had to bring in pumps from elsewhere. About 160 rescuers worked on the response over three days, according to the report.