Yes. We regularly prepare Stormwater Management Plans and Stormwater Impact Assessments — covering pre- and post-development runoff analysis, drainage design, green infrastructure, water quality treatment, and consent requirements. We can also present the plan to council if needed.

A detention tank stores rainwater temporarily during a storm and releases it slowly afterwards — preventing increased flooding downstream. Councils commonly require them in new developments that significantly increase impervious area. We can model your site's runoff to determine whether one is needed and what size it should be.

If there's no council stormwater system to connect to, options include on-site soakage (if the ground allows infiltration), discharge to an open watercourse (if permitted), or detaining water and releasing it at a controlled rate once a connection is established. We assess each site's options and recommend the most practical and compliant approach.

Tricky sites are where we thrive. Our approach is hands-on and solutions-focused. We design earthworks and retaining structures for steep slopes, develop flood mitigation strategies for low-lying sites, and find cost-effective solutions for complex terrain. If there's a workable path, we'll find it.

'Three waters' refers to drinking water supply, wastewater (sewage), and stormwater. Yes — we handle all three. We design reticulated networks, detention tanks, pump stations, and water supply systems to meet council and network operator standards.

Yes. We perform redefinition surveys to locate existing boundary marks or replace missing pegs using official survey records and on-site measurements. We can provide marks to assist with fencing purposes and can advise on next steps if the boundary is disputed.

Plan changes can affect proposed projects, but there are options. If a change is not yet operative, your application may still be processed under current rules. If it makes your development more restrictive, we can advise on what this means for your specific proposal. We monitor plan changes across Wellington's councils and will flag any that may affect your project.

A resource consent covers planning and environmental matters under the RMA — land use, subdivision, and effects on neighbours or the environment. A building consent is issued under the Building Act and deals with structural safety and compliance with the building code. Many projects need both — we manage the resource consent and can coordinate with your architect or building surveyor on the building consent side.

We tailor our involvement to your needs. If you already have consent and just need engineering design and as-built surveys, we can step in. If you need someone to manage contractors and council sign-off, we can do that too. We work at whatever level of involvement suits your project.

The typical process: (1) Feasibility and scheme plan — we assess your site and draw a plan showing the new lots. (2) Resource consent — we prepare and lodge the consent application. (3) Engineering design — we design the infrastructure needed to service the new lots. (4) Construction — the contractor installs the infrastructure, with our engineers supervising. (5) Survey and title — our surveyors produce the final plans and lodge with LINZ for new titles.

Placing non-cleanfill material without appropriate consent can result in formal enforcement action, a requirement to excavate and dispose of the non-compliant material at significant cost, and potential liability for any contamination caused. Orogen's cleanfill classification service protects clients from these risks by confirming material suitability before placement.

Most cleanfill consent conditions require visual inspection of incoming loads to confirm material meets cleanfill criteria, a record of the volume and type of material received, and periodic reporting to the consent authority. Orogen can provide the monitoring and reporting service for cleanfill operations, giving operators confidence that their consent conditions are being met.

A resource consent from the regional council is typically required for the discharge of fill to land. The requirement and the applicable rules depend on the volume of material, the receiving environment, and the regional plan provisions. Orogen prepares and manages the consent application and provides the technical assessments required to support it.

We assess material against the MfE Cleanfill Guidelines, which exclude materials containing contaminants, biodegradable matter, processed wood products, and other specified substances. Visual assessment is the starting point; where contamination is suspected, we arrange laboratory testing to confirm the material's classification.

Cleanfill is uncontaminated and inert. Controlled fill (or managed fill) contains materials that are not clean but can be disposed of at licensed disposal facilities under controlled conditions. Contaminated fill must be disposed of at a landfill licensed for contaminated waste. Orogen assesses fill material to determine which category it falls into and advises on appropriate disposal.

Cleanfill sites require assessment against the MfE Cleanfill Guidelines, a site assessment to confirm suitability (no significant ecological, cultural, or groundwater sensitivity), and in most cases a resource consent from the regional council for the discharge of material to land. Orogen provides the environmental assessment and consent support for cleanfill site establishment and operation.

Cleanfill is uncontaminated, inert material such as soil, concrete, and rock that can be disposed of at a cleanfill site without significant risk to the environment. The New Zealand Waste Management Guidelines define cleanfill criteria. Material that does not meet cleanfill criteria requires disposal at a licensed landfill or other appropriate facility.

If the final site condition does not comply with the consent conditions, the non-compliance must be remediated before certification can be issued. Orogen will clearly document any shortfalls found during the final inspection, advise on what is needed to achieve compliance, and re-inspect once remediation is complete.

The s224(c) approval process requires evidence that all consent conditions have been met. Where consent conditions include environmental requirements, Orogen's environmental certification provides that evidence. Without it, the council will not issue s224(c) and titles cannot be registered.

Survey as-builts record the positions and levels of constructed infrastructure. Environmental as-builts record the final condition of the site's environmental controls: the locations of any permanent stormwater treatment devices, revegetation areas, riparian plantings, and other features required by the consent conditions. Orogen prepares both as a coordinated package for s224(c) applications.

We carry out a final monitoring and inspection of the site, confirm that all ESC devices have been removed or appropriately decommissioned, verify that all disturbed areas have been stabilised or revegetated, review the monitoring record against the consent conditions, and issue a signed certification letter or report.

Most resource consents include a condition requiring the developer to provide environmental certification at the completion of earthworks, at the end of the construction period, or at both. The specific requirements are set out in the consent conditions. Orogen identifies these requirements at the start of the project and manages the certification process.

Environmental certification is a formal sign-off by a qualified engineer or environmental professional confirming that the construction works have been completed in accordance with the consent conditions and the approved environmental management plans. It is required before the consent authority will issue a compliance certificate or s224(c) approval.

Yes. Orogen provides independent environmental audit services on projects where the client wants an independent check on the environmental performance of their contractor or their design engineer's monitoring. Our audit reports provide an objective assessment against the consent conditions and environmental management plans.

Orogen advises the client and contractor immediately and recommends remediation action. We communicate proactively with the consent authority to notify them of the breach and the steps being taken to remedy it. Proactive notification and prompt remediation significantly reduce the risk of formal enforcement action.

We prepare monitoring reports in the format required by the consent conditions, which may include photographic evidence, device condition ratings, and a compliance summary. Reports are submitted to the consent authority at the frequency required by the consent. We communicate any non-compliance issues immediately so they can be resolved before a formal inspection.

The condition of all ESC devices, evidence of any sediment discharge or environmental incident, compliance with dust and noise management measures, the state of exposed soil surfaces, the condition of stabilisation measures, and any changes to the site that might affect the adequacy of the ESC plan.

An environmental audit is a formal, structured assessment of a project's compliance with its consent conditions and environmental management plans. Audits are sometimes required by consent conditions at specific project milestones, and are also used by clients to independently verify their contractor's environmental performance. Orogen provides both scheduled and independent audit services.

Environmental monitoring involves regular site visits by Orogen's environmental engineers to observe the condition of the site, check that ESC and other environmental controls are in place and functioning, and confirm that construction is being carried out in accordance with the CMP and consent conditions. We document findings and photographs in a monitoring report.

CMPs are living documents that must be updated when material changes occur, such as a significant change to the programme, a new sensitive receptor, or an unexpected ground condition. Orogen manages the update process, including notifying the consent authority if required by the consent conditions.

We prepare the plans based on the approved design and consent conditions, then review them with the contractor before submission to the consent authority. The contractor's input on construction methodology, programme, and traffic management improves the practical quality of the plan. We also review the plans with the council's compliance team before finalising.

An Earthworks Management Plan (EMP) focuses specifically on the earthworks phase of construction: cut and fill methodology, material classification and disposal, compaction standards, geotechnical monitoring, and ESC during earthworks. It is more technical than a CMP and is often required alongside it. Orogen prepares both, coordinating the content so there is no duplication or conflict.

Construction programme and phasing, traffic management and access, parking and deliveries, noise and vibration management, dust control, work hours, ESC measures, spill response, emergency contacts, community communication, and the management of any specific consent conditions relevant to the site. Orogen tailors the CMP to the specific consent requirements.

CMPs are typically required for developments in urban areas, near sensitive receptors (schools, hospitals, residential neighbours), or in environmentally sensitive locations. The requirement is written into the resource consent conditions. Orogen prepares CMPs that meet the consent conditions and are practical for the contractor to implement.

A Construction Management Plan (CMP) is a document required by many resource consents that describes how the construction activities will be managed to avoid, remedy, or mitigate adverse environmental and community effects. It covers traffic management, noise and vibration, dust, work hours, ESC, and emergency response.

Most consents include ESC inspections at defined hold points (before earthworks begin, at completion of each stage, and before final stabilisation). Some councils also carry out unannounced inspections. Orogen's monitoring programme anticipates these inspections and ensures the site is in a compliant state when they occur.

Construction sites are dynamic: earthworks progress, weather conditions change, and the configuration of the site shifts over time. Orogen updates the ESC plan as the project progresses and advises the contractor on any changes needed to maintain compliance. We respond quickly to weather events or inspections that require ESC adjustments.

Undersized or poorly maintained sediment retention ponds, silt fences blocked with sediment and no longer functioning, unstabilised bare soil left exposed during wet weather, and construction entrances that allow mud to track onto public roads. Orogen designs ESC to avoid these common failures and monitors during construction to ensure devices remain effective.

Sediment retention ponds, silt fences, rock check dams, stabilised construction entrances, fabric filters, level spreaders, berm drains, hydroseeding, and jute matting for early stabilisation. Device selection is based on the specific site conditions, catchment areas, and the volume of stormwater to be managed.

We assess the site's topography, soils, catchment areas, and weather exposure, then design a staged ESC plan that specifies the devices and measures required at each phase of construction. The plan identifies critical control points, device specifications, installation timing, and maintenance requirements. It is submitted with the resource consent application.

Sediment is one of the most damaging pollutants to freshwater and coastal environments. Fine sediment clouds waterways, smothers aquatic habitat, and degrades water quality for downstream users. Councils enforce ESC conditions actively; breaches can result in stop work orders, fines, and significant reputational damage. Orogen designs ESC to work in NZ's variable weather conditions.

Erosion and sediment control (ESC) refers to the measures used on a construction site to prevent soil erosion and to capture any sediment before it can leave the site and enter waterways. ESC is required by resource consent conditions on almost all earthworks and development projects.

An environmental consultant provides advice on environmental effects, policy, and ecology. An environmental engineer applies engineering skills to manage environmental risks: designing ESC systems, calculating sediment loads, specifying treatment measures, and certifying that works meet environmental standards. Orogen provides environmental engineering services, with a practical focus on getting development built correctly.

Yes. Orogen manages the full environmental compliance lifecycle: preparing the environmental management plans, designing the ESC and other controls, monitoring during construction, reporting to the consent authority, and certifying completion. You engage us once and we manage the environmental track through the whole project.

We act as the technical interface between the consent conditions and the contractor's day-to-day site management. We carry out monitoring visits, identify issues, advise the contractor on remediation, and report to the consent authority. This collaborative approach means problems are resolved at site level rather than through formal enforcement.

Sediment discharge from exposed soil surfaces, erosion of cut batters and fill slopes, contamination of stormwater by construction materials and fuels, disturbance of ecological values or heritage features, and dust generation. Orogen's environmental team designs controls to manage each of these risks for the specific conditions of your site.

We prepare the environmental management plans required by consent conditions, design the ESC measures, carry out regular monitoring during construction, report to the consent authority, and certify compliance at completion. We are embedded in the project team, which means environmental issues are identified and resolved quickly before they become compliance problems.

Construction sites are one of the largest sources of sediment and pollutant discharge to waterways in urban areas. Resource consents include environmental conditions that must be met throughout construction, and breaches can result in enforcement action, fines, and suspension of works. Orogen helps clients meet their environmental obligations so construction can proceed without interruption.

Orogen provides erosion and sediment control design and monitoring, construction management plans, earthworks management plans, environmental compliance monitoring, environmental certification, and cleanfill environmental services. We work across residential, commercial, and infrastructure projects throughout New Zealand.

We design for buildability, specifying materials and configurations that local contractors can install efficiently and that the network operator can maintain. We also consider future network extensions when sizing pipes, to avoid situations where under-sized pipes create problems for subsequent stages of development.

Design standards vary by operator but typically require a minimum residual pressure at the meter under peak demand conditions, and a minimum flow rate to meet fire flow requirements. Orogen designs to the specific standards of each operator and verifies compliance through network modelling where required.

Each water supply network operator has its own design standards, approval process, and connection requirements. Orogen prepares designs to the relevant standard, submits for operator approval, and manages the approval process. For projects near the boundary of the water supply zone or with complex connection requirements, we arrange pre-design meetings with the operator.

NZS4404 and the network operator's standards set out the fire flow requirements for new residential and commercial development. These typically require the reticulation to provide a specified flow rate and duration at a minimum residual pressure. Meeting fire flow requirements sometimes requires larger pipes than would otherwise be needed for domestic supply.

When the existing network cannot provide the required pressure and flow to all lots under peak demand conditions, including fire flow requirements. Orogen assesses the existing network at the feasibility stage to identify whether an upgrade is needed and what it is likely to cost.

Water supply design covers the reticulation of potable water from the existing network to each new lot. This includes pipe sizing, pressure and flow analysis, connection to the distribution main, meters, and any booster pumping where pressure is insufficient. The design must meet the network operator's standards for residential or commercial supply.

Yes. We use wastewater network modelling tools to assess the impact of the additional flows from a new development on the existing network, identify potential surcharging or overflow points, and determine the required mitigation measures. This modelling is often required by network operators as part of the approval process.

Attenuation typically adds cost to the wastewater infrastructure, as it requires additional pipe volume or dedicated storage chambers. However, the alternative, an upgrade to the receiving network, can be significantly more expensive. Orogen advises on the most cost-effective solution for each project.

Peak flows in a wastewater network occur during and after rainfall events when groundwater and surface water infiltrate into the system. Managing peak flows means designing the development's reticulation to limit the rate at which these peaks are passed to the receiving network, protecting network capacity and reducing overflow risk.

We model the peak flows from the development and the available capacity in the receiving network, then size the attenuation storage to limit the discharge rate to what the network can accommodate. The storage design is integrated with the gravity reticulation layout to minimise additional cost.

When the network operator's capacity assessment shows that the receiving wastewater network will be overloaded by the peak flows from the new development. This is increasingly common as older networks reach capacity and new development is required to manage its own peak flows rather than exacerbating surcharging in the existing system.

Wastewater attenuation stores peak flows within the development's reticulation system to reduce the peak discharge rate to the receiving network. Storage is typically provided in oversized pipes or dedicated storage chambers. It is used when the receiving network cannot accept the full peak flow from the development during wet weather.

Yes, where the network operator agrees to accept the pump station into their network. Requirements typically include compliance with the operator's design standards, installation by an approved contractor, a defects liability period, asset information records, and payment of ongoing network charges. Orogen manages the vesting process on your behalf.

Pump stations have ongoing electricity, maintenance, and servicing costs. Pumps require periodic replacement (typically every ten to fifteen years), and control systems and electrical components also have limited lifespans. Orogen advises on the whole-of-life cost implications when recommending a pump station solution.

We design to the network operator's specific pump station standards and submit the design for their review and approval before construction. For vested pump stations, this process is mandatory. Orogen maintains current knowledge of each operator's standards and has established relationships with their technical teams.

This depends on whether the pump station is vested to the network operator (council or water authority) as part of the subdivision compliance process. Vested pump stations are maintained by the network operator. Private pump stations serving individual lots or buildings are the responsibility of the property owner or body corporate.

When the finished ground levels of the development site are too low to drain by gravity to the existing wastewater network, a pump station is needed. This is common in low-lying areas, back lots, and sites where the existing network connection point is uphill from the development.

A wastewater pump station is a facility that lifts wastewater from a low point to a higher point where it can drain by gravity to the reticulated network. It consists of a wet well (where wastewater collects), submersible pumps, a rising main (pressurised pipe), a control panel, and associated electrical and mechanical equipment.

Yes. Gravity networks are the standard and preferred solution; pressure networks using pump stations and rising mains are used where gravity drainage is not achievable due to topography. Orogen designs both, and advises on the relative costs and maintenance implications of each option.

We prepare the design to the network operator's standards, submit for their technical review, and manage the approval process. For larger developments, we arrange pre-design meetings with the network operator to confirm expectations before finalising the design. This avoids costly redesign after the operator's review.

If the existing network cannot accommodate the additional flow from the development, a network upgrade is required. Orogen assesses the receiving network capacity at the feasibility stage and advises on the likely cost and scope of any upgrade required. This cost can be significant and affects the viability of the development.

Wastewater design follows the network operator's engineering standards, which typically reference NZS4404, the Water New Zealand guidelines, and the relevant infrastructure design manual. Orogen designs to the specific standards of each network operator in our area and maintains current knowledge of any updates.

We start by establishing the capacity of the receiving network and the connection point. We then design the internal gravity network, sizing pipes for the calculated peak flow with appropriate freeboard. Where gravity drainage is not possible, we design pump stations and rising mains. All designs are submitted to the network operator for approval before construction.

Sewerage design covers the collection and conveyance of wastewater from new lots to the existing reticulated network. This includes gravity pipe networks, manholes, and (where gravity drainage is not achievable) pump stations and pressure mains. The design must meet the network operator's standards and have sufficient capacity for the development.

Soak-pits require periodic inspection to check for blockage of the inlet or the surrounding soils. The inlet chamber should be cleaned out if sediment accumulates. Properly designed soak-pits have a relatively long maintenance-free life, but neglect can lead to reduced performance or failure. Orogen's designs include access for inspection and maintenance.

Not all councils accept soak-pits, and requirements vary. Some require specific design standards; others require a resource consent. Orogen will confirm the relevant council's requirements before recommending a soak-pit solution so you are not investing in a design that the council will not accept.

A soakage test (typically a falling head permeability test or a modified Philip-Dunne test) is required to measure the infiltration rate of the soil. The test is carried out at the proposed soak-pit location, at the design depth. Orogen can carry out or arrange the testing as part of the design process.

Permeable soils with a measured infiltration rate sufficient to dispose of the design storm without the soak-pit overflowing, adequate depth to the seasonal high groundwater table, and a site area sufficient for the required soak-pit size. Orogen carries out infiltration testing before designing a soak-pit to confirm the site is suitable.

Soak-pits work best on sites with permeable soils (such as well-drained gravels or sandy soils) and sufficient depth to groundwater. They are commonly used in areas where the council does not permit connection to a piped stormwater network, or where the site is too remote for a connection to be practical.

A soak-pit (also called a soakage pit or soakhole) is an underground chamber filled with gravel or other permeable material that allows stormwater to infiltrate into the ground rather than flowing to a piped network or waterway. They are used where soakage is the preferred or only stormwater disposal option.

Yes, and this is often the most cost-effective approach. A shared treatment and attenuation device serving a whole subdivision is typically cheaper to build and maintain than individual devices on each lot. It does require appropriate legal arrangements (easements or reserves) to manage the shared infrastructure. Orogen designs shared systems and coordinates the legal arrangements.

Most treatment devices require periodic inspection and cleanout to maintain performance. Maintenance requirements should be considered at the design stage because they affect the whole-of-life cost of the infrastructure. Orogen includes maintenance requirements in the design specifications and can advise on long-term maintenance planning.

We model the catchment hydrology and the required discharge limit, then size the attenuation storage to ensure the post-development peak flow does not exceed the pre-development or permitted rate. The storage can be above ground (pond) or below ground (tank or proprietary system) depending on site constraints.

Raingardens (bioretention cells), proprietary catch pits with inserts, gross pollutant traps, sediment forebays, constructed wetlands, and permeable pavement. Device selection depends on the pollutant to be removed, the available space, the flow rate, and the maintenance requirements. Orogen recommends devices that are effective and practical to maintain long term.

Stormwater treatment is required when the development discharges to a sensitive receiving environment, when the site generates significant pollutant loads (such as car parks or industrial areas), or when the regional consent requires it as a condition. Auckland's GD05 guideline and Wellington's LGWM stormwater requirements both mandate treatment for certain development types.

Attenuation controls the quantity of stormwater: it slows the peak flow from the site so that downstream pipes and waterways are not overwhelmed. Treatment addresses the quality of stormwater: it removes pollutants such as sediment, nutrients, and hydrocarbons before discharge. Many developments require both.

A straightforward site-level assessment might take one to two weeks. A complex catchment-wide model for a large development can take four to eight weeks. We will give you a clear timeframe and scope when you contact us.

Yes. Orogen models the pre- and post-development flood extents and levels to demonstrate that the development does not increase flood risk on neighbouring land. This is a common resource consent requirement for developments in or near flood plains.

If the flood model shows that the design flood level on your site exceeds the minimum floor level set in the district plan, you will need to raise your floor level to provide the required freeboard above the flood level. Orogen's modelling provides the specific flood level data that feeds into your building designer's floor level calculation.

It tells you the predicted flood level on the site for the design return period (typically 1-in-100-year), whether your proposed development encroaches on the flood plain, what floor level you need to build to, and whether your development will affect flood levels on neighbouring properties.

We use industry-standard tools including SWMM, HEC-RAS, and InfoWorks ICM depending on the complexity of the modelling required. Model selection is based on the catchment characteristics, the required outputs, and the council's preferences.

Flood modelling is required when a site is in or near a flood-prone area, when the council's hazard maps show a flood constraint on the site, when a resource consent condition requires it, or when the development is large enough that its effect on the receiving stormwater network needs to be quantified.

Flood modelling uses specialist hydraulic software to simulate how water moves through a catchment and across a site during a design storm event. It predicts flood levels, flood extents, and flow velocities, which informs development layout, floor level requirements, and infrastructure design.

Pipe sizes and gradients to convey the design storm without surcharging, inlet capacity to handle peak inflows, attenuation storage volumes to limit peak discharge rates, and treatment device sizing to meet water quality standards. Orogen designs to the council's specific storm return periods and level of service requirements.

We engage with the council's engineers early in the design process to understand their specific requirements and to get early feedback on our proposed approach. For complex catchments or large developments, we arrange technical meetings with the council before finalising the design. This avoids late-stage redesign driven by council feedback.

Raingarden devices, proprietary gross pollutant traps, bioretention areas, sediment forebays, and wetland treatment systems. Treatment device selection depends on the site constraints, the volume of stormwater to be treated, and the council's specific requirements. Orogen recommends the most cost-effective solution that meets the consent requirements.

Yes. We use industry-standard hydrological modelling software to model stormwater flows for the design storms required by the council. Modelling results demonstrate that the proposed infrastructure manages runoff to within the accepted limits, which supports both the design and the resource consent application.

A stormwater management plan (SWMP) is a technical document that describes how the development's stormwater will be managed in accordance with the council's requirements. It typically includes a description of the catchment and receiving environment, the proposed infrastructure, modelling results, and the management and maintenance arrangements. Orogen prepares SWMPs for council approval.

New developments create impermeable surfaces (roofs, driveways, roads) that increase stormwater runoff rates and volumes compared to the pre-development site. Without management, this increases the risk of flooding, erosion, and water quality problems downstream. Council standards require developers to address these effects as part of the development.

Stormwater design establishes how rainwater falling on the development site is collected, conveyed, treated, and discharged. It includes pipe networks, inlet structures, manholes, attenuation devices, and treatment systems. The design must manage both the quantity and quality of stormwater to meet the council's requirements and protect the downstream environment.

We size stormwater attenuation to limit peak flows to pre-development rates, design treatment devices to meet water quality standards, and model the interaction of the new infrastructure with the receiving environment. The goal is development that does not impose costs or risks on neighbouring properties or the wider catchment.