Stormwater discharges, the occupation by associated infrastructure, and its maintenance has resulting effects within the Coastal Marine Area. This is a part of the existing environment and this application does not seek to add new outfalls to the CMA. If this was required in the future, then a standalone consent would be sought for that outfall and its associated effects in the new location considered at that time. This section considers the effects relevant to these existing structures and to the discharges sought to be authorised through this application.
Section 6.8 above has considered the effects on water quality from discharges in the freshwater environments. The contaminants are the same for the Coastal Marine Area but it is the receiving
environment that is different. This section provides an assessment of the effects on coastal water quality, ecology and the physical effects of the stormwater network, specifically the outfall pipes in the coastal environment. The disturbance and occupation of the Coastal Marine Area by, or in connection with, the use, maintenance, repair, replacement, or removal of any pipe or outfall structure is a controlled activity within the Coastal Marine Area. As such legalising their physical existence and ongoing maintenance is part of the scope of this consent7. The matters of control set out in the TRMP for the relevant rule relating to occupation (25.1.5.7) are very broad encompassing ‘Measures to avoid, remedy, or mitigate any identified adverse effects of the activity’ emphasis added. The matters discussed below are considered to be those relevant to the occupation aspect of this application.
6.9.2 Effects of Occupation, Maintenance Works and Discharges – Coastal
The effects of erosion and scour can be generated by tidal or wave action in relation to the structure, and by the quantity and velocity of the discharge when it leaves the outfall. The effect of this differs between outfall points due to their size, volumes of discharge, and location within the coastal area. Typically, outfalls in the estuarine areas have little effect from tidal and wave action due to the lower energy in these environments.
They can however develop channels similar to that found where small streams enter these areas. This is shown in the image below of the outfall opposite 67 Motueka Quay. From the aerial image it is apparent that historically a channel was excavated in this location to facilitate stormwater discharge. However, the
channel has stabilised and naturalised with no current need for this level of disturbance. The regular flow of discharge generally maintains the channel while the area immediately below the outfall point has also stabilised.
7Note the flood gates at Wharf Road, and Old Wharf Road (Woodford and Thorp Drain), Motueka (Asset ID SWFGWHARFR-17924; SWFGWOODLA-23018; and SWFGTHORPD-18176) are specifically excluded from this
Figure 25: Stormwater outfall opposite 67 Motueka Quay (source: Top of the South Maps)
Disturbance and maintenance in situations like this are generally limited to ensuring the backflow prevention valve remains clear and operational. At times this may require wheeled or tracked vehicle access to the location. This will be infrequent and limited to the extent necessary to carry out the maintenance works.
Less frequently larger storm events or deposition over time results in coastal stormwater outlets being buried by sand or gravels. When this does occur, machinery is used to clear and expose the outlet. When this work is undertaken disturbance will be kept to the minimum required to undertake any works. Materials cleared are those which naturally occur on the beach and will therefore be retained on the beach as part of the natural environment. Subsequent tidal and wave action quickly returns this to a natural appearance.
Another of the larger outfalls is located at Tait St, Ruby Bay. This is a large concrete structure with associated rock protection placed around it. There is no evidence of erosion or scour caused by the discharge, and with the rock protection in place any caused by wave and tidal action is also controlled. The Ruby Bay coast is a very dynamic area and this rock riprap protection extends approximately 2.5km along this section of the coast. Its placement in the context of the stormwater outfall is in keeping with this much larger coastal protection arrangement. Maintenance required after storm events is also very likely to be required in other areas of the coastal protection and would be carried out in conjunction with this.
Figure 26: Other discharge points, such as that shown at Mapua have little related erosion, scour or disturbance required due to existing coastal protection. The protection itself may need replacement or repositioning on occasion
The effects of erosion and scour, where this occurs, can be managed through the continuation of existing maintenance activities. Disturbance caused by this activity, including disturbance caused through required maintenance activities on the asset itself are kept to a minimum required to carry out the activity. It should be noted that whilst the effects have been considered here this work does in fact meet the permitted criteria of rule 25.1.5.5 ‘Permitted Activities (Disturbance or Occupation of the Coastal Marine Area)’ in relation to avoiding or mitigating erosion effects. The exclusion to this is item b) stating that the activity relates to an authorised structure or work. The structures are not all currently authorised, but should this consent be granted they will be. This enables disturbance for works in relation to erosion protection to be carried out as a permitted activity.
An example of a structure holding a current resource consent (RM171120) is the Broadsea Ave Stormwater Outfall situated 300m further south down the coast than that shown in Figure 26. Works were required on this structure due to storm damage. At the time of works the opportunity was taken to reduce the length of the structure. The resource consent held for this structure can be surrendered should this current consent application be granted. The proposed conditions of consent will ensue that ongoing effects of maintenance activities are effectively managed as anticipated through the conditions of RM171120.
In summary the effects of erosion and scour, including disturbance related to avoiding or remedying this, plus disturbance for maintenance works are considered to be minor. The discharge points in sheltered waters, require little maintenance and have stabilised over time. Any works are minimal and restricted to that necessary to carry out the activity. Those outfalls in more active coastal areas are protected in conjunction with wider protection of the coast.
6.9.3 Effects on Coastal Water Quality and Marine Ecology
In the Tasman region there is evidence of adverse effects on the health of organisms from sedimentation in the Waimea Inlet and the wider Tasman Bay in particular. The other estuaries and receiving environments are also impacted by sedimentation received from the urban catchments and from other sources that contribute to these areas. As for fresh surface water receiving environments these effects are not solely attributed to discharges from the urban catchments that are subject to this application. Urban stormwater does play a role to varying degrees in the different areas of the CMA to which it discharges. Section 6.8 in relation to the freshwater environment has set out a discussion around the relevant contaminants and these also cause similar effects to coastal water quality and ecology. These effects have occurred for many years and has resulted in the environmental conditions that currently exist. Results of monitoring carried out within the Waimea Estuary has shown that contaminants associated with stormwater do exist within this
environment.
As has been outlined in this application the proposal is to carry out incremental improvement actions into the future to ensure that the contaminant load reaching the coast is reduced. This will be achieved through the actions set out in the CMP’s to be developed as required by the conditions volunteered in this application.
Council’s improvement actions will include works on the existing network but also through regulatory control on new development and on new stormwater infrastructure through changes to the TRMP and to the recently developed Land Development Manual 2019.
This proposal, and other Council actions, result in appropriate management of sedimentation from stormwater and over time has the positive effect of reducing sedimentation and entrained contaminant transport into the receiving environment.
6.10 Effects on Māori Cultural Values
The assessment below is provided as a general overview of cultural matters in relation to this application and provides a board understanding of cultural issues. Cultural matters have been incorporated in the
development of the Richmond CMP through Council and iwi working as partners in the drafting process.
This has helped to inform the resource consent development. This application does not include a specific Cultural Impact Assessment (CIA), however CIA’s will be a requirement of the development of CMP’s for each urban development area. This, and the submission period on this application, will enable iwi to highlight any specific matters that are relevant in individual UDA areas.
The health of the natural world, and specifically including water is of fundamental importance to iwi. As noted in the Urban Stormwater Catchment Strategy the following matters are of Significance for Tangata Whenua:
Contamination of habitats and loss of waahi taonga species
Farming, horticulture, forestry, industrial operations and residential uses all contribute to a reduction in water quality. Given that current land use patterns are intensifying, and urban areas are
expanding, tangata whenua iwi are concerned that contamination of the land and water resources will increase and the health of the taiao/natural environment will deteriorate further.
Key concerns relate to the adverse effects on aquatic ecology from alterations in water temperature, the content of suspended solids and the chemical composition of storm water entering waterways.
Tangata whenua iwi are concerned about specific impacts on species migration through the
migration route to inanga spawning grounds. Contaminated stormwater could result in a change in habitat and the subsequent loss of waahi taonga species, such as the Kokopū. The ability for tangata whenua iwi to harvest kai/ food from this area would be diminished as a result. Other key concerns are maintenance work to scrape out the riverbed to clear for flood zone, the removal of existing sparse habitat and riparian margins along the river, and the kōura and native fish exposed to the sun because there is no shade available.
Diminishing mauri of the wai
For tangata whenua iwi, an over-arching concern is the diminishing mauri / life force of catchments as a result of urban and contaminated storm water discharges. The mauri of the wai / water flowing through the catchments is deteriorating and resources that rely on wai/ water for their survival (flora and fauna; native fisheries and bird life taonga species) are being compromised. This concern extends to the mauri of the coastal and estuarine habitats. Land use activities are intensifying throughout the District and subsequently the risk of contaminants entering the waterways through stormwater run-off is increasing.
When the mauri of water is diminished, it loses its vitality and life force, and the people that depend on this taonga will ultimately suffer. The diminishing mauri of in-stream species and habitats and of the estuarine and coastal species and habitats is therefore of great concern to tangata whenua iwi.
Destruction or contamination of waahi tapu
There is a high risk that storm water contaminating waahi tapu / sacred places in and adjacent to waterways. Rising stormwater flows, accelerating erosion and increasing contaminants entering water environments in the catchment all have the potential to destroy or contaminate waahi tapu.
Ability to practice Kaitiakitanga
Tangata whenua iwi have a responsibility as kaitiaki / guardians to sustain healthy wai / water for future generations. This is an intergenerational obligation to uphold the mana of the people through this process. At the heart of kaitiakitanga is the restoration of the mauri of the wai, to ensure the waters are not degraded further. Contaminants entering the waterways via the stormwater systems weaken the ability of tangata whenua iwi to act as kaitiaki over ancestral lands and waters – this in turn undermines the ability of tangata whenua iwi to exercise rangatiratanga / chiefly authority over the wai in the rohe/ district.
The matters identified above have been informed from previous documents which have been produced for similar projects and more significantly from engagement with iwi during the development of this approach to stormwater management. The previous documents referred to are:
• A Māori Cultural Impact Assessment of Storm Water Management in the Richmond Catchment, Tiakina te Taiao, February 2014.
• Moturoa / Rabbit Island Reserve Management Plan, Te tūhinga hukihuki Mahere Whakahaere o Moturoa, Tasman District Council, September 2016.
It is recognised that these documents and engagement to date does not address all cultural aspects of stormwater discharge from all UDA’s in the Tasman Region. The intent of the stormwater management framework, and through conditions of this consent, is that a Cultural Impact Assessment will form part of the development of each Catchment Management Plan. This will enable specific effects within each catchment to be identified and then addressed.
In more general terms water is part of a perpetual cycle between Ranginui (the sky father) and Papatuanuku (the earth mother). The health and wellbeing of water resources, in all their forms, is inextricably linked to the health of the iwi and the natural world. Water connects all other taonga in the catchment and the catchment provides the link from the mountains to the sea. These catchments, through whakapapa, are linked to māna whenua iwi and have been used for centuries to supply life. Iwi are kaitiaki of the catchments and responsible for protecting the mauri of all waters. Mauri gives being and form to the rivers and streams and maintaining and enhancing the mauri is a central principle in management of wai.
Stormwater management plays a key role in the health of the environment and the various receiving waters.
This is therefore directly relevant to maintain the mauri of these waters. The matters identified in the AEE are therefore all relevant to the outcome in terms of cultural effects. This application proposes to set in place a range of actions with the intent of improving the environmental outcomes which will in turn assist with improving cultural outcomes.
The protection of sites of cultural significance (which includes archaeological sites) is also an important aspect of managing the effects of this proposal. Ensuring cultural sites are acknowledged and protected will be a feature of planning physical works on the stormwater network. There are three key opportunities to ensure this does happen:
1. Cultural sites can be identified by Council and iwi during the development of the required Catchment Management Plan in each area.
2. The physical works maintenance programme will be circulated each year giving the opportunity for iwi to identify specific works which may be near to a site of cultural importance and may require specific attention or the services of an iwi monitor.
3. Council staff internal checks when works are being planned in particular areas.
During the development of the Stormwater Management Framework, Urban Stormwater Catchment Planning Strategy, the initial Catchment Management Plan for Richmond, and this consent application consultation has been carried out with iwi. This was with the intent of ensuring any specific matters of relevance, or effects, were identified early and addressed. This process has reinforced some of the matters which have been apparent from previous engagement and knowledge. This includes:
• All waterways are ngā taonga tuku iho (sacred treasures and resources) to Tangata Whenua.
• Access and the ability to utilise waterways is of fundamental importance.
• The fundamental vision needs to be about sustaining the natural world first, other anthropocentric outcomes, such as community health and enjoyment will follow.
It is apparent from the assessment carried out above and due to the importance of water to Māori that the stormwater network and its discharges can have cultural effects that are more than minor, particularly if untreated and managed. As is set out in the mitigation section of this application, and in the attached Stormwater Management Framework and Urban Stormwater Catchment Planning Strategy, this wider project, of which this consent is one aspect, is intended to improve the environmental effects of stormwater.
6.11 Amenity and Recreational Effects
This section focusses on amenity and recreational effects. These effects can also be considered to be cultural effects on the wider population, as distinct from the Māori Cultural Effects noted above. The amenity values and recreational use of rivers and coast form a cultural connection to these areas for many people.
The assessment below addresses the amenity and recreational aspects of these areas.
6.11.1 Amenity Effects
The coastal outfall structures are associated with all UDA’s which discharge directly to the Coastal Marine Area and have the key amenity effects relevant to this application as they require consent. The amenity effects along river banks is of less relevance in terms of this application as those discharge pipes and physical infrastructure are permitted activities with no consenting included in the scope of this application.
The maps and descriptions in section 3 show where the various outfall structures are. In relation to coastal structures the UDA’s concerned are Richmond, Motueka, Mapua / Ruby Bay, Kaiteriteri, Pohara, Patons Rock, and Collingwood.
In some cases the actual outfall structure is not in the Coastal Marine Area. It will discharge to a natural stream channel, or a man-made channel that has become naturalised, which in turn discharges to the Coastal Marine Area. These outfall structures are not included within this section. An example are the outfalls at Ligar Bay / Tata Beach.
The photos below show two typical outlets. The photo on the left is of the discharge point at lower Toru St, Mapua into an arm of the Waimea Estuary adjacent to the Mapua Leisure Park Causeway. The photo on the right is the discharge point at lower Old Wharf Road into the estuarine area behind the Motueka Sandspit.
Note the second small discharge point which is visible further along the beach.
Figure 27: Typical coastal stormwater outfalls.
These are typical of the type of coastal outfall structures that are in place and operated as part of the public stormwater network. The visual effects of these do, to a degree, detract from the natural character of the foreshore and coastal environment. They are not a natural feature and cannot be designed to look natural.
They are however an expected and necessary consequence of urban development and associated stormwater / flood control. Each outfall is maintained in good order to ensure efficient and long-term functionality, but also to lessen adverse visual (and safety) effects of degraded metal, concrete and other materials.
This necessity of location in the Coastal Marine Area is recognised by the NZCPS 2010 as there is a lack of viable alternatives. This offers a degree of mitigation as the need for the infrastructure is understood by the community. The infrastructure within the scope of this application is also existing and has therefore become part of the visual environment. This also applies to maintenance works, and any associated discharges, as these are a necessary part of the management of this infrastructure. When maintenance works are
undertaken these will be controlled through the volunteered conditions of this application to ensure they are well managed and limited to the extent required. With these measures in place controlling the works, and the works being for a necessary purpose which avoids additional adverse effects from blocked or failed infrastructure any remaining adverse effects are considered to be minimised and to be acceptable.
In relation to adverse effects of the stormwater discharge itself this is also an expected part of the management of urban stormwater. Discharges from the urban network which are of sufficient volume to cause discolouration generally only occur during times of heavy rainfall when the rivers are also flooding, and water is running off from surrounding land surfaces. The contribution from the urban network constitutes a small portion of this. In saying this an improved stormwater network with better sediment control will reduce the amount of sedimentation running out to the rivers and the CMA and therefore improve this outcome.
6.11.2 Recreation Effects
Stormwater from the UDA’s subject to this application enter a variety of rivers, streams, lakes and estuaries throughout the region. Many of these environments are also used for recreational purposes. Tasman District Council monitors many of the popular swimming and recreational water sport locations in the region and makes this information available on the Council website. This ensures people have accurate availability of water quality information in these areas.
In this website Council does have the following statement:
‘The risk of catching an infectious disease from swimming in clear, clean water is usually low. However, after rainfall, contamination occurs through runoff into waterways and there is an increased chance that you may