Infrastructure Strategy Wairau land drainage areas and land use changes Options to address it Implications of the options (financial and non- Implications of the options (financial and non- financial) Options to address it financial) are employed Further extend the land Benefits Possible but unknown environmental effects of chemical drainage areas on an residues. adhoc basis when Responds to land use changes in a timely way. requested to do so by Costs Manual clearance Benefits landowners. Doesn’t provide for integrated solutions within a A conventional mechanical removal system with known catchment. environmental impacts Difficult to implement a fair cost recovery plan Costs Preferred Option Benefits Disturbance of river and stream beds, and impacts from Scheduled land drainage Managed and cost-effective approach for Council. sedimentation reviews, to consider extensions of the land Increased land productivity and subsequent indirect More expensive. drainage area integrated benefits to the region from greater flood protection with rate review. Damage to stream profile leading to increased Costs ‘canalisation.’ All costs to borne by benefitting properties through the 2.3 Climate change classified rate. Managing the impact of coastal storm waves and sea level rise 2.2 Environmental expectations on drainage Weed control Options to address it Implications of the options (financial and non- financial) Options to address it Implications of the options (financial and non- financial) Pro-actively upgrade Benefits wave-lap erosion control Retain the current level of service for flood protection and Use of herbicide Benefits measures and prepare land drainage. Cost-effective. Manual clearance is between 6 and 10 plans for up to three times more expensive than herbicide. Costs are likely to additional drainage pump Reduced storm damage remedial costs. increase as landowners demand improved disposal of stations. Planning preparation for sea-level rise but physical works cleared weeds. deferred until greater clarity on the extent of climate Gradual die-back of targeted weeds has less impact on change effects. native flora and fauna. Costs Costs Capital costs to be determined following the review. Additional cost of environmental impact monitoring of React to storm wave Benefits herbicides on aquatic life. Ensure safe working practices 2018-2028 Long Term Plan Page 210