Part 1 - Palmerston North City Council

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gemconsulting preventing further erosion. These areas can then be topped up later from above with no further disturbance to the river bed or active channel. The ford will be used for machinery to cross the river when maintaining or repairing the rock lining and will be occasionally used to transport rock to Stockpile Site 3 if and when required. It is expected that this may amount to 15 loads of rock every 10 years or so. Effects on in‐stream habitats, spawning habitats and fish passage It is unlikely that the finished works will result in any significant effects on in‐stream habitats, spawning habitats or fish passage. Currently the cliff is actively eroding and slipping into the river resulting in a very dynamic environment that is not suitable for supporting in‐stream or spawning habitats. The works will result in a stable channel environment and the rock lining will also provide gaps and shelter between rocks suitable for some fish species. It is noted that rock linings can result in the permanent preclusion of riparian vegetation or bank shading, however in this instance there is no riparian vegetation or shading currently provided in the area. Fish passage will not be impeded by the finished works. The Manawatu River will flow against the new rock lining and fish will be able to swim up or down river as usual. Fish passage will also be maintained along the realigned portion of the Mangaotane Stream. The unnamed tributary will continue to have a small drop into the Manawatu River as it currently does so no change is expected to fish passage along this stream. Effects on channel, bank or bed stability The intent of the works is to improve the channel, bank and bed stability to prevent further erosion of the river bed and ANZAC Park Cliff in the immediate location. It is anticipated that there will only be positive effects on channel, bank and river bed stability as a result of the proposed works. Effects on flood flows The finished works will not have an effect on the flood flows of the Manawatu River. The rock lining will have a design height equal to that of the annual return flood level and any floods above this height will simply flow over the top of the wall as they do for other similar rock linings. The first four metres of fill placed on the rock lining by PMB Landco Ltd will be lined by reject quarry rock to protect the slope from any further erosion during flood events. The works are also being done to ensure the integrity of the existing City stopbanks and to ensure safe conveyance of flood flows through the City Reach of the Lower Manawatu Flood Protection Scheme. Effects on public access to the river and recreation The potential for public access will be greatly enhanced by the proposed works. Currently there is no safe public access along the left bank of the Manawatu River in this location and access to Pari Reserve is difficult with the reserve being located within a steep sided valley. The Palmerston North City Council has indicated a desire to see a public access route along this side of the river. The design of the proposed works will see a seven metre wide bench on top of the rock lining between the river and the toe of the re‐contoured cliff. This area will provide access for future inspections and maintenance of the finished rock lining and groyne. Subject to PNCC funding and works, the bench will also enable a safe public access link from ANZAC Park to Pari Reserve to be formed. Whilst the river will be located closer to the right bank it is expected that the beach on the inside of the corner will reform naturally over time providing good access to the river. Overall the finished works will provide improved access to the river, its margins and the nearby reserves and will eliminate a real risk to public safety. Effects on natural character Currently the river flows directly into the cliff and makes a dramatic turn to the right. This sharp change in river flow combined with the active slipping of the cliff provides for a very active scene for viewers. There is little human modification at the river's edge on the left bank of the river. Although not considered to be a significant habitat, the Pari Reserve is vegetated but this is also being actively eroded by the river. 20
gemconsulting This natural character of the area will change as a result of the proposed works. The river channel will be located closer to the right bank of the river and the river will take a more constant and gentler curve around the corner as it did previously. The rock lining and upstream groyne will be visible for much of the time, the exception being in flood events that exceed the annual return period flood level. The works may also see the introduction of a public access to the left bank of the river. Some people may also find that the presence of people on the left hand side of the river detracts from the character of the area. It is not expected that there will be any change to any habitats offered by the Pari Reserve, and it is likely that there will be improvements in habitats offered by the river due to the stabilisation of the erosion from the cliff above. The realignment of the Mangaotane Stream is not likely to change the natural character of the area to any great extent. Currently the stream runs through exotic scrub before joining the river at the subject site and is extremely difficult to identify from the right bank of the Manawatu River. Once realigned, the stream will continue to flow through similar vegetation as it does now and would still be difficult to identify. The access track between the river crossing and subject site on the left bank would likely be visible and could detract from the natural character that bank. It is intended to top soil and grass all access tracks to help prevent erosion and it is expected that the track would quickly revegetate with light scrub similar to that around it after its use has ceased. Effects on infrastructure (MWRC monitoring station and Fitzherbert Bridge) The MWRC has a river monitoring station near the former Teachers College. This station is of considerable importance to the Regional Council as it is used to monitor levels and flow rates of the river and in turn this information is used in and to assess various resource consents and to inform policy development. Any changes to the accuracy of the recordings from this station are likely to have on‐going effects and could possibly affect third parties through the monitoring of resource consent conditions. Changes in the accuracy of recordings from the station can occur though changes in the river bed. Regular monitoring of the river bed is carried out to detect natural bed changes and the flow rating is maintained accordingly. The proposed works have potential to cause changes to the channel bed profile that could affect the flow ratings from the recording station. The applicant has been in discussions with the Council’s Catchment Information Department regarding this issue and has reached an agreement that is satisfactory to both departments of the Council. A copy of the agreement is attached to this report as Appendix G. The Fitzherbert Bridge crosses the Manawatu River approximately 1km downstream of the subject site. The proposed works will not affect the bridge in any way. Effects on existing flood protection infrastructure One of the reasons for carrying out the proposed works is to provide long term protection for existing flood protection infrastructure. If left to erode the cliff, the river will eventually change direction and start to undermine the flood protection structures on the right bank of the river. The proposed works will prevent that from happening. Overall there will only be beneficial effects on the flood protection infrastructure. Effects on adjacent and residential properties Due to the erosion in this area very little of the works will actually occur in the river bed as surveyed. In fact most of the works will occur on land titles that are owned by the PNCC (Lot 13 DP 72989 and Cliff Road reserve), PMB Landco Ltd (Lot 51 DP 382375) and the Hargreaves title (Section 219 Town of Fitzherbert). Essentially, the surveyed river bed is the adjacent property on the city side of the subject site and PMB Landco Ltd and the PNCC own most of the land adjacent to the site on the left bank. Some of the reasons for the proposal are to protect land adjacent to the river from undue erosion and to protect flood protection structures from being undermined in the future. It is considered that the proposal will have significant benefits for the adjacent land. There are some residential properties on Waicola Drive that are starting to erode. The works will protect these properties by preventing the river from undermining the eastern cliff below these properties. 21
Page 1 and 2: good earth matters gemconsulting Ma
Page 3: APPLICATION FOR RESOURCE CONSENT Se
Page 7 and 8: gemconsulting TABLE OF CONTENTS 1 I
Page 9 and 10: gemconsulting 1 INTRODUCTION The Ma
Page 11 and 12: gemconsulting Some 400 metres of th
Page 13 and 14: gemconsulting take up to 150 workin
Page 15 and 16: gemconsulting 3.3 Monitoring and Ma
Page 17 and 18: gemconsulting 5 REGULATORY FRAMEWOR
Page 19 and 20: gemconsulting beaches which specifi
Page 21 and 22: gemconsulting Flood Protection Zone
Page 23 and 24: gemconsulting 5.4 Objectives and Po
Page 25 and 26: gemconsulting The extent and nature
Page 27: gemconsulting Other sources of nois
Page 31 and 32: gemconsulting It is considered that
Page 33 and 34: gemconsulting Policy 16.2 requires
Page 35 and 36: gemconsulting existing stop banks o
Page 37 and 38: gemconsulting Policy 8 This policy
Page 39 and 40: gemconsulting fish, will ensure tha
Page 41 and 42: gemconsulting The Attractive Commun
Page 43 and 44: gemconsulting The Mangaotane Stream
Page 45 and 46: gemconsulting 8 RESOURCE MANAGEMENT
Page 47 and 48: gemconsulting the significance
Page 49: gemconsulting Appendix A LOCATION P
Page 53: FIGURE B: LOCAL PARKS, RESERVES & W
Page 57: FIGURE D: LAND HOLDINGS WHERE WORKS

Part 1 - Palmerston North City Council

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