The Jabour Weir pool on the Richmond River at Casino provides vital storage for Casino’s drinking water.
The weir pool extend 12km upstream from the weir and has an approximate storage capacity of 1,700 megalitres, with Council drawing around 7.5 megalitres per day for potable water production from the raw water pump station within the weir pool.
Although the weir overflows most of the time, the prolonged drought has reduced the Richmond River flows significantly, with flows over the Jabour Weir as low as 1 megalitre per day.
Unfortunately this has led to the weir pool gradually being drained through the Denil fishway, which allows fish passage across the weir and to some extent environmental flows downstream of the weir.
The Denil fishway is approximately 200mm lower than the weir, so keeping the fishway open during the current low flow conditions is draining the weir pool.
To prolong the weir pool storage, Council applied to NSW Department of Primary Industries for the temporary closure of the fishway, allowing the weir pool to refill to its normal level where it overflows over the weir.
The permit conditions allow for the closure of the fishway only during low flows. Once flows normalize (flows in excess of 4 megalitres per day) the fishway will be reopened to maximise the opportunity for fish passage.