Whakatāne District Council infrastructure staff will be updating progress on high-priority stormwater upgrading projects in Whakatāne and Ōhope to the next meeting of the Council’s Projects and Services committee on 4 September.
Infrastructure General Manager Tomasz Krawczyk says project planning activities are advancing quickly, and the update report would be seeking Council approval to proceed with several key initiatives.
“Flood protection works for the Wainui te Whara Stream catchment are being developed in conjunction with the Bay of Plenty Regional Council, and we expect to have the scope and estimated costs of the projects involved confirmed for approval by both Councils in November, with detailed designs and tendering getting underway in December,” Mr Krawczyk says. “In the meantime, we’ve already commenced work on a series of small detention structures in the upper catchment, which will regulate flood flows from about 20 percent of the area the stream drains.”
He says the nature of the structures meant they did not require resource consents or involve significant capital cost, but they would nevertheless make a useful contribution to limiting the peak stream flow during extreme rainfall events. “We’ve also completed the design work on two log-deflection structures planned for the lower gorge and have lodged resource consent applications with the Regional Council. Again, these are not complicated or extremely costly structures, and we anticipate that construction may be completed by the end of October.”
Surveying has also started in the lower catchment between Valley Road and Hinemoa Street to provide accurate data for the hydraulic modelling required to update channel capacity and identify improvement priorities.
Meanwhile, flood mitigation project plans have been developed for the areas immediately to the west and east of the Maraetotara Stream in Ōhope. The plans were discussed with residents at a public meeting on 11 August and include the installation of new stormwater pipelines discharging into the stream and the creation of flood mitigation storage capacity in other areas. If approved by the Council, contracts for the work could be awarded in October, with the physical works being undertaken over summer, outside of the peak holiday season.
Pump station upgrades and culvert and channel improvements are also planned for the Apanui catchment in Whakatāne. Scoping and design work is underway, and Mr Krawczyk says it’s hoped that a contract to undertake the work will be awarded before the end of November, with the physical work to be completed by May 2015.
Funding for the stormwater upgrades has been included in the Council’s 2014/15 Annual Plan, with $2.04 million earmarked for the Apanui catchment works, $1.48 million for Wainui te Whara works and $1 million for work in Ōhope.