|Algal growth in closed water bodies is one of the main factors of water pollution. Thus, to reduce water pollution, it is necessary to decrease the nutrient load in these water bodies. Even if the nutrient load of stormwater is known, its relation to algal growth in stormwater could be unclear. To understand which nutrients from stormwater contribute to algal growth, river water was sampled for stormwater at intervals of several hours during the rainfall period. For this sampling, four sites in the Inbanuma Basin, each differing in terms of land use, were chosen. At each of these sites, nitrogen, phosphorus, metal, and algal growth potential (AGP) were measured. The stormwater runoff characteristics of nutrients and AGP were studied at each site. The relationships among land use, metal concentration, and AGP were statistically analyzed. The results showed that the AGP load increased in basins with many plowed fields and decreased in those with high urbanization. Further, the correlations among Mg2+, B, Ca2+, and AGP were positive.