Flood Retarding Basin Under ConstructionOnline Images - 1980
To hold back water in flood conditons, the basin's normal outlet is deliberately restricted by its small diameter culvert pipe. As water increase exceeds discharge capacity, level in the basin will rise until it reaches a vertical outlet connected to a much larger diameter discharge culvert. Surges will be quickly dumped whilst the greater volume of flood water is retained in the basin for gradual discharge.
Characteristics: 1 photograph : col. ; 11.5 x 6.5 cm.