Keila has the largest watershed among the three study areas (Table 1). According to the land use and land cover database Estonian National Topographic Database, most common land use types in the three study basins being arable land, forested land and wetland. The dominant land use for all study areas is arable land, covering around 45–60% of the area. Kunda basin is only covered 5% by wetland, while the corresponding land use coverage in Keila and Valgejõe are 12% and 16%, respectively. Forested land accounts for 28%, 40% and 44% of the land surface in Keila, Kunda and Valgejõe, respectively. All case-study regions have relatively flat slopes, with an average slope of around 1%.