Flood protection and drainage schemes
Across Canterbury, flood protection and drainage works are carried out in dedicated rating districts. Management of rating districts is split over three geographical engineering areas: Northern, Central and Southern.
About the rating districts
Click on the area below to find out further information about your rating district and what is happening in these areas.
The Northern District covers the Waimakariri-Eyre-Cust Scheme to the Kaikoura Rivers and Kaikoura Drainage Schemes. Each geographical area is broken down into specific rating districts. Your rates notice will tell you if you are a ratepayer of a river rating district.
Current works in the area
View the current works in the Northern district.
The Central District covers the Halswell Drainage and Te Waihora to Ashburton Hinds Drainage Scheme. Each geographical area is broken down into specific rating districts. Your rates notice will tell you if you are a ratepayer of a river rating district.
Current works in the area
- View the current works in the Central district.
The Southern District covers the Rangitata River to the Lower Waitaki River. Each geographical area is broken down into specific rating districts. Your rates notice will tell you if you are a ratepayer of a river rating district.
Current works in the area
- View the current works in the Southern district.
Asset condition summary
Asset condition is a measure of the physical state of the asset and is visually assessed by staff on an annual basis. We have several methods to monitor the condition of the rating districts assets.
This information is critical to the overall life cycle management of the assets, with regards to maintaining the asset at minimum cost, whilst maintaining the required level of service, forecast renewal requirements and prioritising works. The assets are inspected depending on the asset type and the importance of the asset.
Condition information is currently available for some of Environment Canterbury’s river and drainage scheme assets, but not all. For very localised schemes, the asset management compliance report is sufficient to summarise the condition of assets, these
are completed on a yearly basis.
The asset types that have had a documented condition assessment include:
- Stopbanks
- River berms (includes assessment of the relative erosion protection value of trees, groynes and rockwork)
- River fairways (not included in asset valuations but a critical part of scheme capacity)
- Drains.
Condition assessments are typically on a 1-5 scale, where 1 means excellent condition, 3 may be adequate or with minor deficiencies and 5 is very poor condition, or not fit for purpose.
Culverts and other structures tend to be inspected frequently and have generally also had some condition assessment but the documentation for these assessments is ad hoc and not easily summarised.
River rating district liaison committees
We manage 59 river and drainage rating districts, each doing works on specific parts of rivers or drainage networks.
Twenty-five of these are large enough to warrant representative river rating district liaison committees.
The committees are the voluntary eyes and ears on the ground for their local river flood and erosion protection and drainage works and influence the overall direction of flood and erosion protection and drainage works.
Committees meet once or twice a year to comment and advise on the state of the river and the proposed works and budget for the coming year. They have an influence on the targeted rates set for each river and the timing of significant works (although final decisions are made by Environment Canterbury).
The committees focus on whether their community has an adequate and appropriate level of safety, security and resilience from flooding and erosion or an adequate and appropriately resourced drainage network.
While committees occasionally discuss matters such as incorporating amenity or biodiversity objectives into erosion protection works, or the influence of water takes on the river rating district works, those issues are not their primary focus.
Rating district meetings
Check out our events calendar for details on all of our river rating district meetings including date, time and venue.