Our work

Projects

300+ projects across New Zealand since 2016. The portfolio spans residential subdivision, flood hazard assessment, stormwater infrastructure, and agricultural development across Hawke's Bay, Manawatu–Whanganui, Auckland, and beyond.

Greenfield Subdivision 2–90 lots, roads + 3-waters
Urban Infill 2–20 lots, compact services
Flood Assessment 1D and 2D HEC-RAS
Stormwater Neutrality All major NZ councils
Infrastructure Upgrade Pipes, stopbanks
CPEng Review Independent sign-off

Selected Case Studies

All client names are confidential.

★★★
Greenfield subdivision · Marton, Rangitikei · 74 lots · 2021–2025

Henderson Line, Marton

Full infrastructure design for a 74-lot subdivision including roads, stormwater, wastewater, and water supply. Analysis of box culvert (1500×1000mm, $700K material cost) versus dual 1050mm circular pipes ($100K) identified a $600,000 saving for the client. 10-year stormwater design with HEC-HMS. Construction supervision 2021–2024. S224c certification for Stages 1 and 2 completed 2025.

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★★★
Greenfield subdivision · Marton, Rangitikei · 90 lots · 2019–2022

Hereford Heights, Marton

90-lot greenfield subdivision on 6.95Ha. Horizons Regional Council required a 200-year flood design standard - higher than the national 100-year requirement. SCS and TP108 modelling for the large Folly Stream catchment. Datum reconciliation between NZVD2016 and WVD1953 (0.543m difference) was critical for setting correct finish floor levels across all 90 lots. Multi-stage S224c (Stages 1, 2, and 3).

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★★★
Flood hazard assessment · Waipukurau, Central Hawke's Bay · 2020

Tukituki River Flood Assessment

Q100 flood flow estimated using three SCS method variants: Original SCS (λ=0.2) gave 894 m³/s; Brazilian SCS (λ=0.05) gave 1,129 m³/s (+21%); Auckland TP108 (Ia=max 5mm) gave 1,186 m³/s (+25%). A 6GB LiDAR dataset of 120 million points was processed using Cloud Compare. Cyclone Gabrielle February 2023 confirmed the conservative approach: TukiTuki stopbanks breached at seven upstream locations, but Lots 1–5 on the assessed site had no flooding.

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★★★
Subdivision · Marton, Rangitikei · 41 lots · 2022–2026

Kensington Road, Marton

A wetland identified by WSP's specialist report was rebutted using aerial photographs from Retrolens dated 1942, 1949, and 1982 - demonstrating the pond appeared only after 1982 and was not a pre-existing natural wetland under NPS-FW 2020. A 500m³ detention swale was designed against a required 388m³. Wastewater trunk main (Ø375mm AC) realigned through the site. Multi-agency consent: Rangitikei DC plus Horizons Regional Council.

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★★★
2D flood study · Glen Eden, Auckland · 2025

Glendale Road, Auckland

Full 2D HEC-RAS flood hazard study required as an Auckland Council resource consent condition. 1m×1m model grid built from 2024 LINZ LiDAR. Two overland flow paths identified: OLFP1 at 0.469 m³/s and OLFP2 at 4.28 m³/s. Flood depths reach 1.2m at the 1% AEP event. Pedestrian hazard mapped in accordance with Auckland Council assessment criteria.

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★★★
Stormwater neutrality · Napier, Hawke's Bay · 6 units · 2025

Barker Road, Napier

The first project completed under Napier City Council's new SW-S1 stormwater neutrality rule. 16,000L total detention storage in four 4,000L Tanksalot tanks with 13mm orifice outlets. Working through the SW-S1 methodology on this project established the calculation approach and reporting template now applied to all subsequent NCC stormwater neutrality applications.

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★★★
Subdivision · Bulls, Rangitikei · 2024

George Street, Bulls

The existing 300mm stormwater pipe was inadequate; replaced with a 525mm main and 450mm orifice plate. A 290m detention swale with 1,020m³ volume was designed to achieve stormwater neutrality on poorly drained Rangitikei soils. Horizons Regional Council resource consent was required because the discharge point changed from Henratty Drain to Tutaenui Stream - a watercourse modification triggering regional consent obligations.

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★★★
Agricultural stormwater · Otakiri, Bay of Plenty · 2023–2024

Commercial Farm, Otakiri

Stormwater design for three large farm buildings (12m × 122.5m each) on pumice soils with no council drainage network available. Field soakage rates of 800–1,720mm/hr recorded; a conservative design rate of 400mm/hr adopted (50% reduction per standard practice). Groundwater at 1m depth constrained infiltration pit design to 0.8m maximum depth. Required storage 43,868L; NZBC E1 criterion 42,014L. A three-RFI building consent process with Whakatane District Council.

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Other Projects

Project Location Type Scale / Key detail
Murphy Rd, Taradale Napier 2-lot subdivision 2×2,000L detention tanks; NCC SW-S1; 15mm orifice (kerb discharge) / 30mm orifice
Flower St, Bulls Rangitikei 3-lot subdivision Pallic (Flaxtonford) soils - poorly drained; soakage vs kerb analysis; 11.5m³ total detention; NIWA HIRDS RCP 6.0
Rayner Lane, Marton Rangitikei 9-lot brownfield Existing sewer main through site requiring easements; one-way access; S224c certified January 2026
Avenue Rd, Napier Napier 4-lot subdivision Low-lying site; floor RL 3.0m vs ground RL 2.20m (800mm above ground); site discharge 6.9 L/s; EA25001 approval
Kennedy Rd, Napier Napier 5-unit residential NCC SW-S1; 5×2,000L tanks; 20mm orifices
Downing St, Glenfield Auckland 3-lot urban infill HEC-HMS; 2×3,700L tanks; Auckland NDC
Kempton Park Lane Havelock North Single dwelling Hillside SN8 pipe design; anchor blocks; erosion control
Crystal Ave, Glendene Auckland 5-lot infill Full infrastructure; WW pump station for Lots 1–3
Gloucester St, Taradale Napier Secondary dwelling HEC-HMS 10–250yr return periods; datum reconciliation; NCC kerb discharge limit
Durham Drive, Havelock North Hastings BC RFI response Site inspection; 200mm pipe capacity; 1,809m² catchment
Nigel Rd, Browns Bay Auckland 17-lot terrace housing Individual detention tanks; deep infrastructure DTI 4.1–5.35m
Pukepapa Rd, Marton Rangitikei 6-lot subdivision Full 3-waters; EPA approved; NZS 4404
Tomoana Rd, Hastings Hastings 7-lot subdivision ESCP; infrastructure coordination; HDC consent

Auckland CPEng Review Portfolio

Independent CPEng review and sign-off of infrastructure reports for Auckland residential developments.

Project Key detail
Woolfield Rd, Papatoetoe Stream discharge design; supercritical outlet; rip-rap energy dissipation
First Ave, Kingsland Swimming pool chlorine dissipation modelling; basement pump station
Clinton Ave, Te Atatu 20 units; Aquacomb pod retention/detention system; SMAF-1 zone
Tarawera Terrace, St Heliers Flood-prone site; HEC-RAS model review; multi-year Auckland Council consent
Blockhouse Bay Rd Piled foundations due to flood depth; HEC-RAS modelling required by council
Clematis Ave, Hamilton Hamilton PC12 stormwater reuse; flood level analysis
Gosford Drive, Botany Foundation bridged over existing stormwater pipe; Watercare monitored area
Aberfeldy Ave, Highland Park THAB H6 zone; SMAF-2; Watercare capacity-constrained area
Grande Vue Rd, Papatoetoe HEC-RAS flood zone; detention tanks; S92 response
Murillo Place, Henderson Thrust bore stormwater main extension; detention tanks

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