| Whangamarino River | |
|---|---|
| Location | |
| Country | New Zealand |
| Physical characteristics | |
| Source | |
| • location | Lake Waikare (modified due to flood control scheme) |
| Mouth | |
• location | Waikato River @ Meremere |
The Whangamarino River is a lowland river of the Waikato Region of New Zealand's North Island, draining the Whangamarino Wetland and associated farmland catchment. The river converges with the Waikato River just north of Meremere. The main tributary is the Maramarua River, which starts in the Hunua Ranges and forms the northern catchment of the Whangamarino River.
The natural Whangamarino River system, especially the main branch (the southern catchment), has been highly modified due to the lower flood protection scheme of the lower Waikato River.[1] Prior to these floodworks, the Whangamarino Catchment was unconnected with Lake Waikare. However, due to the Lower Waikato-Waipa Flood Control Scheme, constructed in the 1960s, Lake Waikare was transformed and used for flood retention storage when the nearby Waikato River was in flood. During flood events, the Waikato River now overflows into the transformed Lake Waikato via the Rangiriri Spillway (and the redirected Te Onetea Stream). When the Waikato River conditions are suitable, the flood waters are discharged from Lake Waikare into the Whangamarino River catchment through the artificial Pungarehu Canal.
While the flood scheme has permanently changed the ecology of Lake Waikare, it has also provided broader benefits for the community.[2][3]