Tauwhareparae Farms Dam Design Case Study
The design and construction of the Lowden Hills farm dam has enabled the harvesting and storage of 37,100m³ of water for stock water reticulation, thus allowing increased stocking rates and feed utilisation in dry periods.
Tauwhareparae Farms Ltd farm a total area of 11,253ha (6,000 effective) grazing approximately 52,000 stock units. A farm water storage dam has been designed and constructed on Lowden Hills to enable the harvesting of 37,100m³ of water for stock water reticulation from a catchment area of 45 hectares. AgFirst Engineering involvement included dam location, design and project management.
Hydrological modelling was used to determine flood flows, leading to dam design which would withstand extreme rainfall events. Working alongside civil works contractors, AgFirst Engineering supervised the dam construction monitoring key parameters such as compaction and soil voids. The end result is a large scale dam, providing water storage and reticulation to 1500 hectares.
- Dam embankment of 8.5m with sidewall batters of 3:1.
- Minimum standard of compaction is 95% max dry density.
- 15m wide crest width, enabling unimpeded movement of stock and vehicles.
- Concrete intake and spillway system to enable constant dam water level during rainfall events.
- Energy dissipater downstream and spillway to avoid damage to the natural water course.
- Rock riprap to reduce erosion from wave lap.