Information on increased water storage:
Information on runoff reduction:
Increased water storage will provide additional capacity to retain and efficiently remove run off from highways, and infiltrate to ground. This will reduce the volume of water reaching the local sewer and Day Brook. Modelled 33% reduction in flow reaching the sewer for 1 in 1 year event
Information on Peak flow rate reduction:
The storage capacity of the rain gardens will result in reduced peak flows reaching the local sewer, as water will be slowed and contained in the gardens.
Information on Maintenance baseflow:
Possible increases to infiltration to groundwater from rain gardens, providing groundwater recharge and baseflows to the brook. However the influence is likely to be minor.
Water quality overall improvements:
Information on Water quality overall improvements:
Rain gardens are designed to always intercept and treat the, often more polluted, first flush of highway runoff, ensuring this polluted water does not reach the Day Brook or the local sewer. However there is no available data for the quality of water flowing into or within the rain gardens.
Soil quality overall soil improvements: