Appendix F - River Control and Drainage Works Programme • Raising low stopbanks at upper Conders and lower Conders area. • Two new rock headed groynes at upper Conders. • Construct new stopbanking to complete the stopbanking between upper and lower Conders areas. • Planting trees as bank edge protection, and in places strengthening with rail iron retards. • Raising low open ended stopbanks on the north bank at Barnetts, Norths and Huddlestones. • Stopbank strengthening work at Upper Barnetts and Hillocks Road. • Berm shaping works at Upper Barnetts, Cravens Road, Wratts Road areas. • Tuamarina pocket stopbank raising. 5.5 Waihopai River (Confluence to 300 metres upstream of SH 63 Bridge) 5.5.1 Design Intentions 5.5.1.1 To clear and maintain a fairway of typically 150 metres width on the river. 5.5.1.2 To provide and maintain bank edge protection for this reach by maintenance of existing rock training banks, by retards and tree planting and as necessary isolated rock work. 5.5.1.3 To prevent overflow on to the Wairau/Waihopai floodplain. 5.5.2 New Works Required • Stopbank on the right bank above the confluence with the Wairau. • Tree planting and piled retards bank protection. 5.6 Lower Opawa/Taylor (up to Wither Road) 5.6.1 Design Intentions 5.6.1.1 To increase the hydraulic efficiency of the lower Opawa by removal of trees growing on the banks or overhanging into the river from upstream of Swamp Road. 5.6.1.2 To increase the effective waterway capacity of the berms and better flow interaction with the main channel by removing impeding banking (much of it natural ‘banking’) and carrying out berm shaping works upstream of Swamp Road. 5.6.1.3 To control vegetation planting on the berms that may impede flood flow upstream of Swamp Road. 5.6.1.4 To reconstruct lengths of narrow, weak and under-height stopbank downstream of Riverlands corner. 5.6.1.5 To repair or replace inadequate culverts through the stopbanks. App F - 5