This section needs to be updated. Would you like to help out? See the To Do List in the forums.
Here is a brief overview of how Karamea manages its stopbanks and floodwarnings. This has been reviewed by WCRC staff and Bevan Langford, chair of the Karamea Rating District. If you have any questions contact Rick Lucas.
Stopbanks and the Karamea Rating District
Stopbanks and river protection works exist on the Karamea River to provide safety to people, animals and property during times of high water. River protections works exist on Granite Creek and Little Wanganui River as well. On an annual basis the Regional Council’s river engineer and our local Rating District Committee inspects and monitors such things as the status of stopbanks and silt build-up which may affect the flow capacities and levels of Karamea’s riverbeds.
As a result of this inspection and discussion, staff from the West Coast Regional Council make recommendations to the rating district’s annual meeting regarding maintenance and improvements to our stopbank system, along with cost estimates for proposed river control work (comprising the Karamea Control Scheme).
The Rating District’s annual meeting is usually held in October, (although the date can vary so check your agenda papers when Council sends them to you). Any foreseeable future maintenance or new works is discussed, and any cost implications are voted on. The result of the vote is recorded and provides advice to the Council when it makes the final decision. The cost of works is paid for by rates, which are apportioned within our community according to the perceived benefits of groups and ratepayers. The Rating District Committee is elected from Karamea ratepayers and may be asked to make decisions on behalf of the rating district where works are considered urgent.
Ensuring that our community is well protected from high-water events is central to these processes. Preparedness is a deterrent against serious flooding.
Flood Warning System and Phone Tree
A flood warning system is crucial when the potential for flooding develops. Heavy rain events and coincidental high tides or low pressure systems magnify the likelihood of serious floods. Our region’s alarm trigger is the water level sensor gauge up in the Karamea gorge. During protracted heavy rains if a river level of 4.0m is reached on the flood hydrograph, the Regional Council’s Flood Duty Officers are alerted. They monitor rising water levels to provide information for the people implementing the Flood Action Plan strategies.
If that occurs the officers phone the councils and key community representatives. The District Council’s civil defence co-coordinator then gets in touch with the local farmers near our rivers who execute a phone tree call-around. If need be, Karamea’s Civil Defence volunteers become involved and, if necessary, direct people to a high ground assembly spot. This location may vary according to individual flooding circumstances.
Radio can become a critical communications link at such times. Coast FM (96.5), Scenicland (90.9), and Karamea Radio (107.5 FM) may provide important updates. The West Coast Regional Council website also provides river level updates at least three hourly during an event (www.wcrc.govt.nz).
Fitness Report on the Health of our Stopbanks
A flood modeling report completed in 2006 indicated that Karamea’s stopbank system is fit to withstand less than a 1 in 20 year ‘highflow’ flood event (mostly due to the present height of our stopbank system). This conclusion was based upon historical data and the expertise of river engineers and hydrologists. It is noted that most flood-prone communities aim for stop-bank protection to a minimum potential 1 in 50 year event. Some cities will raise their level of flood-bank protection to a 1 in 100 year event.
Karamea has chosen to accept and maintain the current, lower standard and a higher level of risk than other communities regarding the maintenance of our stopbanks. The cost of raising the height of stopbanks is considerable for a community of our population. The Annual Meeting of our Rating District is a forum where this can be discussed. Information about our stopbanks, the Karamea Rating District, Flood Warning System and local phone tree can be found on the Karamea Community Website.