During dry weather, water flows pass this diversion structure directly to the treatment plant. During wet weather and high flows, some or most of the flow is diverted to this 35-million gallon basin where the flow is equalized on its way to the plant.
During 2009, improvements were made to the crossover chamber, allowing stormwater from Shockoe Bottom to be directed to the river without mixing with the combined sewer flows. This recent modification is for more efficient operation.
During 2010, the basin was cleaned. Because stormwater flow surges are diverted to and held at the basin, sediment collects there. An estimated 70,000 cubic yards of sediment was removed by the summer of 2010.
Diversion structure improvements during 2010 included refurbishing the bar screen rake in the west end of the structure to assist with the removal of debris, leaves and tree limbs from sewer flows.