Graeme Horrell – Review of MWH’s Pinehaven Hydrology

Expert hydrologist Graeme Horrell reviewed MWH’s Pinehaven hydrology and concludes:
“this rainfall-runoff modelling … [has] large uncertainties … at least ± 100% … This highlights the risk of using just one single event to calibrate the rainfall runoff model, which then feeds inputs into the hydraulic model. … Any further use such as … [for flood mapping] will result in large errors …[and] in unreliable design values for the Pinehaven stream works upgrade.”