The first stage of the Manaia Causeway and Graham's Creek flood protection works in Tairua will be getting underway next Monday.

From this Sunday, the Manaia Rd causeway will be closed for eight weeks as contractors extend the bridge, and means access to Paku Drive will be via State Highway 25 and Ocean Beach Rd.

From this Sunday the Manaia Causeway in Tairua will be closed for eight weeks while flood protection works at both the causeway and Graham's Creek are carried out. Photo: File

The Thames-Coromandel District Council says this Friday additional signage will be going up on Ocean Beach Rd.

'[This is] to ensure motorist and pedestrian safety on this route is maintained during the period of the Manaia Road closure due to the detoured vehicle and pedestrian traffic flows.”

The Graham's Creek flood mitigation works is a collaborative project between Thames-Coromandel District and the Waikato Regional councils.

Over the past 14 months a working party consisting of community representatives, elected members and staff from both councils have helped determine the most effective solution to reduce the impact of flooding in this area and to improve the natural environment.

'The bridge at the Manaia Rd Causeway will be extended by 16m, which will help keep the road open during flooding and allow floodwater to drain more easily,” explains council.

'Meanwhile the regional council will then start floodway improvement works including stopbanks, re-contouring the floodplain to form a floodway and creek channel works. Both pieces of work need to be done in tandem for a successful outcome.”

Information billboards are currently being installed at key areas around the site this week, which explain the works being undertaken and the expected benefits.

Council's Roading Manager Matt Busch says they apologise for any inconvenience the road closure will have for both road users and pedestrians during this period.

'However we believe the completed project will add significant value to the area, through reduced flood risk, whilst improving amenity and biodiversity values.”

Graham's Creek in Tairua. Photo: File

THE PROJECT IN PHASES

PHASE 1: Manaia Rd causeway bridge upgrade – October-December 2015.

• Stage 1 Site establishment and pile driving.
• Stages 2 and 3. Construction of new bridge abutment and foundations.
• Stage 4. Excavation of causeway for new bridge extension.
• Stage 5. Jack up northern end of existing bridge.
• Stage 6. Placement of new bridge deck.
• Stage 7. Construct causeway road, to link with new bridge.
• Stage 8 Install guardrail and site disestablishment

PHASE 2: Floodway improvement works – October-December 2015.

• Stage 1. Land re-contouring and drainage diversion as well as sediment control construction.
• Stage 2. Stream channel enlargement (outside fish spawning season) and floodway excavation.
• Stage 3. Stopbank; overflow floodway weir, culvert and floodgate construction.
• Stage 4. Grassing, stabilisation and finishing Phase 2 works

PHASE 3: Floodway improvement works – February-March 2016.

• Stage 1. Excavation and channel enlargement in the Coastal Marine Area (outside bird breeding season).
• Stage 2. Raise existing stopbank and in-filling.
• Stage 3. Complete stream realignment and infill old stream and drainage channels.
• Stage 4. Grassing, stabilisation and finishing Phase 3 works

PHASE 4: Restoration and Mitigation

• Stage 1, Plant and animal pest control underway.
• Stage 2. Restoration planting May-June 2016