As noted previously, there are sources of suitable substrate identified in the Critical Habitat reach but most if not all is buried to some degree by sand.
To explore the potential of high flows to periodically remove the sand and expose coarse gravel or a suitable substrate for egg adhesion we used the 1974 hydrograph as a test case in a sediment-transport simulation.
We idealized the hydrograph to a steady-flow period of 14 days at a constant discharge of 1300 cms, corresponding to the high-flow period prior to the usual spawning season, to evaluate the spatial pattern and magnitude of erosion and deposition in the Critical Habitat reach.