Those that live, work and play in the Cook Stream and Cooks Beach area know only too well its value. More recently, however, residents in the area have raised a number of concerns with the councils relating to localised flooding in particular. Over time, changes in the catchment and community have resulted in impacts on the floodplain.
Concern around the management of the floodplain and potential flood effects has led the Waikato Regional Council and Thames-Coromandel District Council (TCDC) to develop a draft catchment management plan for the Cook Stream. While the impetus for this was flood management, it is recognised that a holistic and catchment wide approach is needed.
For the purpose of this work the Cook Stream catchment refers to an area of 570 hectares (Figure 1).
|Figure 1: Cook Stream Catchment|
To assist in managing the Cook Stream catchment area, a draft catchment management plan has been prepared and the key findings of this are outlined below. A key action within this plan is to address flood risk in the floodplain, and it is proposed that this primarily be dealt with by adding Cook Stream into TCDC’s Proposed District Plan. This would involve the application of rules, to avoid inappropriate development in the floodplain.
The Cook Stream Catchment Management Plan was initiated due to community and council concerns around the infilling and management of the Cook Stream floodplain and flooding in the lower catchment.
The draft Cook Stream Catchment Management Plan is based on the Waikato Regional Council’s harbour and catchment management plan (HCMP) framework and will at a later date be incorporated into an HCMP for the greater Mercury Bay area.
Development both within and in close proximity to the Cook Stream floodplain has restricted stream capacity and the continued allowance for an appropriate flood corridor. The area is also relatively low lying in relation to commonly occurring flood and sea levels.
It is generally expected that the Cook Stream area will flood during significant rainfall events (such as 50 year and 100 year events). Recently, a few landowners have filled in parts of their property in the Cook Stream floodplain, appearing to worsen the flooding on other properties during more frequent, lesser events (such as 5 and 10 year events). This issue, along with a lack of restrictions for new development in the flood prone area, raise concerns that need to be addressed. New development in flood-prone areas without any limits or restrictions to protect the landowner and neighbouring properties from flooding needs to be managed. When floodwaters are diverted inappropriately it eventually means other landowners have to put in protection works in response.
For more information on rules relating to management of the Cook Stream floodplain, please contact TCDC's District Plan team on 07 868 0200.
The Cook Stream flood area, as modelled by Waikato Regional Council, is shown in Figure 2.