Pranil Wadan

Director

BE Civil, CPEng, IntPE(NZ), CMEngNZ

Pranil is a Chartered Professional Engineer and a recognized leader in design, management and planning of water infrastructure. He brings over 18 years of technical expertise to land development consultancy, specializing in complex stormwater and flood hazard mitigation.

His extensive track record includes delivering resilient infrastructure solutions for large-scale greenfield, brownfield, multi-unit housing, and commercial projects across New Zealand. This work is underpinned by proficiency in advanced hydrodynamic modeling, strategic stormwater design, and detailed flood hazard analysis.

Shaped by years of working closely with developers, planners, and other multidisciplinary teams, Pranil maintains a transparent and collaborative approach. At Flowstate, he provides clear, definitive guidance on stormwater risks, network constraints, and mitigation strategies, helping clients navigate long development cycles with confidence. His focus remains on delivering resilient three-water outcomes, ensuring clear communication every step of the way.

Bidara Pathirage

Principal Engineer

BE Civil (Hons), CPEng, CMEngNZ 

Bidara is a Chartered Professional Engineer with more than 10 years’ experience in stormwater engineering, infrastructure design, and land development.

She began her career in Western Australia’s mining industry, working as a engineer in Perth for three years before returning to New Zealand in 2015. Since then, Bidara has worked extensively on major infrastructure projects across New Zealand, including both greenfield and brownfield land developments.

Bidara has strong technical experience in stormwater management planning, flood assessment, flood modelling, reticulation design, option analysis, and infrastructure planning. She regularly uses modelling software to support robust design decisions and practical project outcomes.

With a clear understanding of the technical, environmental, and delivery drivers that shape complex projects, Bidara works closely with clients, consulting engineers, project teams, and key stakeholders from concept design through to completion.

Gina Nicholas

Principal Engineer

BE Mechanical (Hons) CPEng, CMEngNZ

Gina is a Chartered Professional Engineer with over 15 years’ experience across stormwater, wastewater, and water supply in New Zealand.

She has a strong technical background in hydraulic modelling, flood hazard assessment, catchment management, infrastructure master planning, and long-term network planning. Her modelling experience includes InfoWorks ICM, DHI, H2OMAP, HEC-RAS, HEC-HMS, ArcGIS, and QGIS.

Gina has led stormwater catchment modelling and master planning projects for multiple councils, including mitigation and conveyance assessments, level of service reviews, option development, and capital expenditure planning. Following the 2023 Auckland flood events, she contributed to the Tāmaki Makaurau Flood Recovery programme, undertaking property-level flood hazard assessments and technical reviews.

She has also led wastewater modelling and feasibility work for major growth projects, helping resolve capacity constraints and support future development. Gina works across the full project lifecycle and collaborates effectively with councils, consultants, and project teams to deliver practical, technically robust infrastructure outcomes.

Shakti Singh

Senior Engineer

BEngTech, CPEng, CMEngNZ

Shakti is a Chartered Professional Engineer with over eight years’ experience in stormwater and hydraulic engineering across New Zealand.

He specialises in flood modelling, stream erosion assessment, stormwater strategy, water-sensitive design, and consenting for complex land development and infrastructure projects. His experience spans greenfield development, brownfield regeneration, transport corridors, and neighbourhood-scale stormwater upgrades.

Through the LEAD Alliance, Shakti has played a key role in major Kāinga Ora regeneration projects in Waikōwhai, Northcote, and Wesley, delivering practical stormwater and flood management solutions in complex urban environments. He has also worked with KiwiRail as lead stormwater engineer, resolving drainage constraints within active rail corridors.

Shakti brings strong technical design and modelling capability, together with a practical understanding of consent requirements, stakeholder coordination, and infrastructure delivery. He has also presented multiple papers at national industry events, contributing to technical discussion across the stormwater sector.

Andrew Chen

Engineer

BE Civil (Hons), MEngNZ

Andrew is a civil and environmental engineer with seven years’ experience delivering stormwater, flood modelling, and three waters solutions across residential, commercial, and infrastructure projects in New Zealand and the Pacific. He is currently working towards Chartered Professional Engineer status.

His experience includes stormwater management, hydrological and hydraulic modelling, detention basin design, overland flow path assessment, flood hazard reporting, civil design, and construction-stage support. Andrew has contributed to a wide range of projects, from early concept design and consenting through to construction delivery and post-construction certification.

Andrew is proficient in TUFLOW, HEC-HMS, QGIS, Civil 3D, and Autodesk Storm and Sanitary Analysis. He works effectively within multidisciplinary project teams, coordinating with architects, surveyors, planners, and engineers to support practical, well-integrated design outcomes.

Dr Anbin Li

Engineer

BE Civil (Hons), ME, PhD, MEngNZ

Anbin is a hydraulic engineer with specialist expertise in river engineering, hydraulic structures, sediment transport, scour assessment, and 3D numerical modelling.

He holds a PhD in Hydraulic Engineering from Northwest A&F University and completed a Visiting PhD year at the University of Auckland. His academic research focused on local scour, coupled flow and sediment transport, and advanced numerical modelling, giving him a strong technical foundation in complex river and hydraulic systems.

At Flowstate Consulting, Anbin applies this specialist capability to flood modelling, river engineering, and hydraulic structure projects within the New Zealand water sector. His technical experience includes HEC-RAS and XPSWMM for catchment-scale flood and river analysis, along with Flow-3D and ANSYS Fluent for detailed CFD simulation. He also has hands-on experience in physical hydraulic model testing for scour, energy dissipation, and sediment transport studies.

Anbin’s project experience includes low-head dam scour protection, river improvement and sediment sluicing, flood diversion tunnels, reservoir spillways, bottom outlets, and bridge hydraulics. His work includes model development, calibration, result interpretation, technical reporting, design recommendations, and client presentations.

He has published in several peer-reviewed journals and presented at international conferences in Denmark and China. Anbin works closely with multidisciplinary teams and brings a rigorous, research-led approach to hydraulic engineering projects from concept through to delivery.

Bidara Pathirage

Principal Engineer

BE Civil (Hons), CPEng, CMEngNZ 

Bidara is a Chartered Professional Engineer with more than 10 years’ experience in stormwater engineering, infrastructure design, and land development.

She began her career in Western Australia’s mining industry, working as a engineer in Perth for three years before returning to New Zealand in 2015. Since then, Bidara has worked extensively on major infrastructure projects across New Zealand, including both greenfield and brownfield land developments.

Bidara has strong technical experience in stormwater management planning, flood assessment, flood modelling, reticulation design, option analysis, and infrastructure planning. She regularly uses modelling software to support robust design decisions and practical project outcomes.

With a clear understanding of the technical, environmental, and delivery drivers that shape complex projects, Bidara works closely with clients, consulting engineers, project teams, and key stakeholders from concept design through to completion.