The Empire Wastewater Treatment Plant green roof was constructed as part of a major plant expansion. The plant is located adjacent to the Vermillion River, a designated trout stream. The Metropolitan Council designed the plant’s stormwater management practices to both protect the river and trout habitat as well as to serve as demonstrations of innovative stormwater management. Along with the green roof, the stormwater management system includes two large infiltration basins with native plantings, a native plant garden, permeable pavers, and vegetated drainage swales.

The plant list includes Dianthus deltoides (Maiden pink dianthus), Koeleria glauca (June grass), Petrorhagia saxifrage (Tunic flower), Semmpervivum hybriden (Hen and Chicks), and Sedum spurium (Dragon’s Blood Sedum), set in 6″ of growing medium.