The proposed upgrade of the Pacific Highway between Warrell Creek and Urunga is part of the Pacific Highway upgrade program being implemented by Roads and Maritime Services (RMS) . The project is 42 kilometres in length, commencing at the northern end of the existing dual carriageway highway at Allgomera (referred to as the Allgomera deviation), connecting with the existing Waterfall Way interchange, north of Urunga.
In October 2010 WMAwater reviewed the hydrology, flooding and river crossing aspects of the proposed Pacific Highway upgrade, Nambucca River Crossing, and consulted with Council and residents who have raised issues regarding the impact of the bypass on flooding. The purpose of this review was to assess the technical suitability of the work carried out by SKM, for quantifying the impacts of the proposed Macksville Bypass on Nambucca River flood levels.
In 2011 WMAwater assessed a community proposed alternate route across the Nambucca River floodplain. The Pacific Highway upgrade from Warrell Creek to Urunga has 5 major waterway crossings (Kalang River, Deep Creek, Nambucca River, Warrell Creek and Upper Warrell Creek). WMAwater was engaged by RMS to define the existing flood behaviour within the Lower Bellinger and Kalang Rivers, Nambucca River and Warrell Creek and Deep Creek. The outcomes of this study are to:
- Form the basis for the detailed design of the major river crossings for the Warrell Creek to Urunga Pacific Highway upgrade project; and
- Be extended into a flood study under the NSW Flood Policy and will form the first stage in the management process for these catchment areas by the Nambucca and Bellingen Councils
As part of the study WMAwater:
- established 4 hydraulic models;
- completed a dam break assessment;
- extensive community consulation with affected landholders and Councils;
- sized culverts;
- assessed afflux impacts of platforms to be used in bridge construction;