Urban infiltration in cold climate

The implementation of Sustainable Urban Drainage Systems (SUDS) in the northern hemisphere is confronted with the problem of decreased infiltration during winter because of frozen soils. The goal of this research was to assess the winter infiltration capacity of a grass swale and natural vegetation cover during frequent freeze-thaw cycles. Infiltration was measured with eight single-ring infiltrometers, and by analysing continuous water content measurements in the soil at different depths in the steep (13- 16%), BREEAM certified neighbourhood Urriðaholt. Results suggest that frost formation and infiltration capacity were influenced by vegetation cover: dense grass cover performed equally on a seasonal basis, while infiltration through less dense vegetation covers decreased by 11-54% during winter as compared to summer. Frost was measured for a few days at 5 cm depth in the soil, and concrete frost completely inhibiting infiltration did not form. The results presented are part of an ongoing research.