Omokoroa Stormwater Pond and Earth Dam

Completed in 2019, the Omokoroa SW Pond 02 for Western Bay of Plenty District Council involved construction of a 9m high by 80m long stormwater detention dam and levelling 5 ha of subdivision lots as the dam fill. The site was large, sloping and involved conditioning various types of soils to enable placing and compacting engineered fill for the Dam embankment and the Classic Builders residential subdivision. Approx. 100,000m3 of fill and 40,000m3 of topsoil was shifted, conditioned, placed and compacted throughout the project.

A live stream ran right through the embankment location which required meticulous Erosion and Sediment Control planning and implementation. This included clean and dirty water diversions, silt fences, and a sediment detention pond. All works were undertaken in accordance with the Resource Consent and all Local Authority site audits scored highly.

A 525mm RCRRJ pipe culvert was first constructed adjacent to the live stream before the stream was diverted into the culvert to allow for embankment construction. A number of manholes and other drainage lines were constructed including two 7m deep, 2.3m precast concrete manholes. Fish passages were constructed through the culverts and manholes to allow fish to move through the structure.

A spillway and extensive construction of Reno mattresses and Gabion baskets were completed on the downstream embankment to protect the dam in the event of over topping.