The previous on-site reservoir keeper had no need to deal with that type of vegetation, as it was dealt with before it got to that stage - safely and easily. Furthermore, long-term residents of WB have been clear that seeing overtopping and use of the spillway was 'very rare' prior to 2012. Before forecast periods of heavy rain, the keeper would use the sluices to divert the Todd Brook and other inflow, and lower the water level by use of what one person described as 'the gates at the bottom.' Thus sufficient headroom was maintained - enough, when necessary, to cover for periods of heavy rain during the keepers absence and days off.
Since 2012, several WB residents have contacted the CRT wrt their concerns about the changes they have observed on and around the dam. Their concerns have been dismissed and they have been told they were 'wrong'.
Maybe they were, indeed, wrong, Maybe the breach would have happened even sooner, and more catastrophically, if the keeper had continued diligently keeping the spillway clear of weeds, maintaining appropriate 'headroom' below the spillway, and diverting the inflow according to water levels, expected demand and the weather forecast. Maybe not.
I don't know, do you?