Whakatane-Waimana Rivers Scheme
The Whakatane River system comprises two main branches, the Waimana River and the Whakatane River.
- Whakatane Waimana Floodplain Management Strategy Stage 1 (Update from January 2007) (10 MB, pdf) VERY LARGE DOCUMENT
- Whakatane Waimana Floodplain Management Strategy Stage 2 (1.8 MB, pdf)
Order a copy
To order a copy of the Strategy documents, please contact us. Cost: Stage 1 document, $ 27; Stage 2 document, $15. Alternatively, click on the links above to download copies.
Scheme meeting notes
Bay of Plenty Regional Council has a network of liaison people for each of the EBOP-managed river and drainage schemes in the region. The liaison group members are the representatives for the ratepayers of their particular scheme. Meetings are held with the liaison groups in March and November of each year. Extraordinary meetings are called as required. Below is a copy of the notes from the last cycle of liaison group meetings. For previous later meeting notes contact us on the details below.
|Whakatane-Waimana Rivers Scheme Laision Group meeting notes 19 March 2013||5.258 MB|
The Waimana catchment covers 440 km2 extending 77 km, while the upper Whakatane covers 1100 km2 and extends 112 km with both catchments being relatively narrow and the tributaries short and steep, draining extensive bush covered catchments. The underlying rock foundation over the whole of the area is greywacke.
The Waimana River valley floor is narrow and has few areas of river flats in the upper 48km, but after leaving the main range the floor widens and for the next 19.5 km the river channel is wide and braided.
The final 13km of the Waimana River are through a gorge with the exception of the last 1.6km where it empties on to the valley floor just upstream of the confluence with the Whakatane River.
The Whakatane River rises in the Huiarau Range and quickly drops into a deeply incised valley and there are no significant river flats for the next 64 km until the river flows out of the main range at the upper Ruatoki Valley. At this point the valley floor widens out to an average width of 11600 metres before widening out again at the limeworks.
Below this for the next 6.5 km the river has developed a wide meander belt with considerable areas of shingle bed and marginal river flats.
Below the Ruatoki Bridge which is 26.6 km upstream of the sea, the river is generally more confined due to the establishment of willow edge protection until it reaches the confluence with the Waimana. From there it continues for another 3.5 km before it reaches the Pekatahi Bridge and below this the river is stop banked.
The Whakatane River Scheme is a river and drainage scheme that includes: substantial stop banking of the main river and some major tributaries, floodgates, gravity and pumped drainage outlets, and considerable channel edge (bank) protection and plantings. The scheme includes the Whakatane and Waimana Rivers and the Te Rahu, Waioho and Wairere Tributaries.
The aim of the original scheme was to provide 100 year flood protection along the lower 12.8 km of the river, partial flood protection and channel improvements along the upper 30.4 km of the Whakatane River and 28.8 km of the Waimana River, and improved drainage for approximately 4000-6000 hectares of the Eastern Rangitaiki Plains.
Previous to the scheme extensive flooding was a common event for the low lying areas generally north of the Awakeri-Taneatua railway line, from western drain in the west to Waioho Stream and up the Whakatane River valley. Whakatane Borough was subject to flooding on the western side, and indeed was unable to be developed for housing until after the construction of the nearby stopbanks and channel control works.
Scheme construction commenced in 1965 and was completed in 1981. A scheme review of the lower Whakatane River protection works was undertaken in 1985 following the availability of further hydrologic and hydraulic data. This resulted in some further works which were completed in 1993.
An analysis of flow records for the period 1957-94 shows that the one in one hundred year flood for Whakatane River as measured at the Valley Road recorded, is 2460 cumecs (cubic metres per second). The mean flow of the fiver for 1957-95, at Valley Road, is 57 cumecs. (Surman 1995).
Subsequently the council adopted a three year programme of works which began in 1994/95. That programme includes clearing, training groynes, layering, trenched willows, planting and fencing to return the rivers to a stable meander pattern in terms of width and alignment. Once the plantings and protection works are established, the reaches will be established, reducing repair works currently necessary after most floods.
Maintenance of the scheme is funded by way of a rate struck over the area of benefit. A "classification" (Circa 1969) establishes the relative benefits received by all the lands within the scheme. Bay of Plenty Regional Council reviewed the classification during 1993 and found it remained fair and equitable. Rates for any property are calculated on the basis of land value and benefit classification of that property.
The areas receiving benefits from the scheme amounts to approximately 19,400 hectares and as at 31 January 1996 this area had a land value of about $550 million, and a capital value of about $1,233 million.