Construction starts this week on works to reduce flood risk to properties in the upper and mid Heathcote area.
Since the earthquakes, flooding has increased along the Heathcote River. The Council's Land Drainage Recovery Programme has been investigating the benefits of increasing flood detention storage in the upper Heathcote, around Hendersons Basin. The team has looked at whether this would help homes along the Heathcote River which have an increased risk of above floor flooding as a result of the earthquakes.
Initial modelling results have shown increased floodwater storage in the Hendersons Basin area would have a positive impact in reducing this flood risk downstream. Other mitigation solutions will still be required to reduce this risk to pre-earthquake levels.
The work starting today on two flood detention basins to double the storage capacity at an existing stormwater management area known as Eastman Wetlands, marks the first small step of further works to reduce water levels downstream in the mid and upper Heathcote catchment.
Additional storage in Hendersons Basin will not reduce flood risk in the lower Heathcote, due to the tidal influence in the lower reaches.
To facilitate future projects to increase storage, the Council purchased two properties in Hendersons Basin, totalling nearly 37 hectares, at the end of 2015. Work is currently underway to maximise the storage potential offered by this land, and maximise other storage opportunities within the area.
Work the Land Drainage Recovery Programme is doing across the city to reduce flood risk to pre-earthquake levels.