88 | Upping protection against weather events T T Virginia Wright The Hawke’s Bay region is criss-crossed by rivers and their tributaries. COMMUNITY Hawke’s Bay Regional Council: Resilient River Communities In an effort to make the region better prepared to weather the future effects of climate change the Hawke’s Bay Regional Council is leading four projects united under the name of the Resilient River Communities. These projects, beyond the economically viable reach of funding through local ratepayers can now, thanks to a collaborative funding model supported by $19.2 million from the government’s COVID-19 Recovery and Response Fund, proceed, with input from District Councils, local iwi, communities and businesses. The Hawke’s Bay region is criss-crossed by rivers and their tributaries with different areas requiring different approaches to increase the level of flood protection provided to the communities around them. The Regional Asset Manager for Hawke’s Bay Regional Council responsible for the region’s flood protection assets such as stop banks, culverts and pump stations is Martina Groves. She’s also the acting Manager of the Resilient River Communities which she summarises quite simply. “It’s about increasing protection against more frequent weather events and keeping our communities safe.” The low-lying river plains of the Tūtaekurī, Ngaruroro, Clive and Lower Tukituki rivers is home to the Heretaunga Plains Flood Control Scheme (HPFCS). The council’s goal as part of their long-term plan is to increase the level of flood protection from a one in 100 year event to a one in 500 year event, plus all the other likely smaller events. A combination of erosion protection measures such as upgrading the stop banks and introducing groynes, and measures to enhance the rivers’ ecosystems by planting and protecting the local biodiversity, are planned for key sites across the plains. “We plant willows to slow down the water and protect the edges of the river, and we plant a diversity of other species further out from the edges to increase the biodiversity. We have to be careful as we widen the river berms to make sure we’re not causing any problems further upstream by holding the water up,” explains Martina. The net result will offer additional flood protection to the roughly 82% of the Hawkes Bay’s population whose lives would be affected by an adverse event. Central Hawke’s Bay is home to two projects covering 5 rivers: Tukituki, Makaretu, Tukipo, Waipawa and Mangaonuku. Gravel builds up in the Upper Tukituki and these tributaries where the morphology stops it from naturally moving downstream. The additional funding allowed the Hawke’s Bay Regional Council to work with the Upper Tukituki community to come up with a strategy that brings the cost of extracting the gravel from the area into line with the same job elsewhere within Hawke’s Bay, thus making its extraction an attractive prospect for potential tenderers. The desired outcome is to maintain flood protection to handle a one in 100 year event by increasing the river capacity and so reducing the risk of flooding to farmlands and neighbouring properties in the area. The other project is the first to be completed. For the last 10 years the Waipawa riverbanks upstream of State Highway 50, including the approaches to a bridge on the main route between Napier and Central Hawke’s Bay, have been deteriorating. This project combines hard engineering works designed to encourage the river braids away from the banks, to deepen and widen the riverbed, and to capture the river’s own debris and gravels to shore up the banks; with the planting of thousands of willows and indigenous trees with deep root structures to enhance the riverbanks’ stability, and thus protect the approaches to the bridge for the foreseeable future. The fourth project involves the Wairoa River at the intersection of River Parade Road and Carroll Street and protects the bridge across the river, which provides critical access to Gisborne. Steel sheet piles are being installed to protect around 73 metres of riverbank, watermains in Wairoa have been relocated, and once again targeted planting and com- “We plant willows to slow down the water and protect the edges of the river, and we plant a diversity of other species further out from the edges to increase the biodiversity.” If you need earthworks, pile driving & more, call Dodge Contracting – where perfection brings excellence. // EARTHWORKS // LEVELLING BUILDING SITES // PILE DRIVING // CYCLE TRACK MAINTENANCE // CLEARING DRAINS // DEMOLITIONS // HOLE DIGGING // SITE CLEARANCE // CARTAGE (06) 870 4091 | 207 Hastings St. North, Hastings 4122 dodgecontracting@xtra.co.nz | www.dodgecontracting.co.nz
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