Flood Control and Drainage SchemesKaupapa ārai waipuke

Overview

The Regional Council provides 27 flood control and drainage schemes in Hawke’s Bay to reduce the risk of flood and erosion damage – including by invasive pests - while maintaining a high quality river environment. We maintain networks of stopbanks, hydraulic structures and pump stations and manage the river, stream and drainage channels to ensure they work as expected during floods to help protect life and property.

Many of the stopbanks are now used for cycle trail routes, and at Pākōwhai, the site of a former river control scheme is now a regional park.

Take a look at our video with Craig Goodier of the Regional Council talking about how the Regional Council manage flood control below.

What does the Regional Council do?

The Regional Council has designed and maintains flood control schemes on the region’s rivers to provide protection from storms with up to a 1% likelihood of exceeding capacity once a year - also referred to as a 1 in 100 year flood or 1% Annual Exceedance Probability.

The drainage schemes are typically designed to a standard to manage rain events between 1 in 5 year and 1 in 20 year in size, although this varies.

Why are stock on river edges?

Rivers on the Heretaunga Plains are fenced off for cattle, where land is owned or administered by the Regional Council. We are actively working with private landowners on this, even though the earliest rules to prevent stock entering waterways don’t apply until 2020 (Tukituki catchment). Riverside stock grazing has been part of the Regional Council’s flood control management plan.

Stock grazing has been used in the past as a cost-effective method to keep grass and other vegetation at a manageable level on river edges and stopbanks.

The advantages include helping with flood control.  Taller vegetation causes flood levels to increase.  It traps silt and sand (sediment) and reduces a river’s ability to deal with flood water flows. Dry vegetation is also a fire hazard in our hot dry summers.

The Regional Council leases riverside land to farmers to graze their stock.  Electric fences prevent stock from entering the water on council owned land, though these are vulnerable to small and larger floods, and vandalism.

The income from leasing this land goes to the flood control scheme to offset rates.

Stock exclusion from waterways in the Tukituki catchment is part of the Tukituki Plan. This legally comes into effect in 2020 – as fencing and other farm practices are expensive and take a while to put in place. We are already working closely with landowners and the farming sector to maintain and improve water quality in that catchment. On the Heretaunga Plains, stock exclusion from waterways is part of the TANK collaborative project, where the Regional Council aims to adopt stock exclusion measures as part of a TANK Plan Change late next year.

Find more information on stock exclusion

Environmental Code of Practice

The Regional Council has an Environmental Code of Practice in place which provides clear standards of practice for river control and drainage works. It also documents the environmental enhancement or conservation protection, identifies areas for public access and recreation, and identifies future enhancement or protection requirements.

What can you do?

Ratepayers pay targeted rates for the maintenance of the flood protection works.