Water & Wastewater — Core Service

Stormwater & Flood Management

Evidence-based hydrological engineering to protect communities, infrastructure, and agriculture from the growing threat of extreme rainfall and flooding.

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40+
Flood Studies Completed
1000+
km² Catchment Modelled
25+
Urban Drainage Master Plans
12+
States Covered
Flood modelling and drainage infrastructure by HRP Infra
Climate-Resilient Design

OVERVIEW

Protecting Lives and Infrastructure from Flooding

As urban areas expand and climate patterns intensify, effective stormwater and flood management has become a critical engineering challenge. HRP Infra applies advanced hydrological and hydraulic modelling, GIS-based catchment analysis, and proven infrastructure design to deliver solutions that reduce flood risk and manage surface water responsibly.

Our services span the full spectrum — from city-scale drainage master plans and flood hazard mapping to the detailed design of drainage channels, retention basins, and flood control embankments.

  • Urban & Peri-Urban Drainage Master Plans
  • Hydrological & Hydraulic Modelling
  • Flood Hazard & Risk Mapping
  • Flood Mitigation Infrastructure Design
  • Natural Flood Management (NFM) Solutions
  • Climate Change Adaptation Assessment
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THE CHALLENGE

Why Stormwater Management Matters

Rapid Urbanisation

As impervious surfaces replace natural land, runoff volumes and peak flows increase sharply, overwhelming drainage systems not designed for current growth.

Intensifying Rainfall Events

Climate change is increasing the frequency and severity of extreme rainfall, making previously adequate drainage infrastructure insufficient to protect lives and property.

Ageing Infrastructure

Many existing drainage systems were designed for older rainfall data and lower population densities, requiring urgent assessment, rehabilitation, and upgrade.

WHAT WE OFFER

Our Engineering Services

A complete range of stormwater and flood management services, from hydrological studies through to infrastructure delivery.

Drainage Master Plans

City- and town-scale drainage master plans with catchment delineation, design storm analysis, network capacity assessment, and prioritised capital works programmes.

Hydrological Studies

Rainfall-runoff modelling using rational method, SCS-CN, and unit hydrograph methods, including frequency analysis for 2-year to 100-year return period design storms.

Hydraulic Modelling

1D/2D hydraulic network simulation using HEC-RAS and SWMM for open channels, culverts, pipes, and floodplains to identify bottlenecks and size mitigation works.

Flood Hazard Mapping

GIS-integrated flood inundation mapping showing flood depth, velocity, and frequency for different return periods — essential for land use planning and emergency response.

Flood Mitigation Design

Structural design of retention ponds, detention basins, flood embankments, revetments, and channel improvement works to reduce peak flood levels and protect assets.

Natural Flood Management

Integration of sustainable drainage systems (SuDS), constructed wetlands, and upstream land management strategies to attenuate flows while delivering ecological benefits.

TOOLS & TECHNOLOGY

Software-Driven Analysis

We use industry-leading hydraulic and hydrological software to produce defensible, simulation-backed designs.

HEC-RAS

USACE 1D/2D river hydraulics and floodplain modelling

SWMM

EPA stormwater management model for urban drainage simulation

HEC-HMS

Hydrologic Engineering Center precipitation-runoff modelling

ArcGIS / QGIS

Geospatial analysis, catchment delineation, and flood mapping

INFRASTRUCTURE WE DESIGN

Physical Solutions

Storm Sewers & Box Culverts

Underground and surface drainage conduits sized for peak design flows, including inlet structures, manholes, and outfall designs.

Retention & Detention Basins

Above- and below-grade storage basins to attenuate peak stormwater runoff and reduce downstream flood risk.

Flood Embankments & Bunds

Earth and masonry flood embankments with stability analysis, seepage control, and freeboard provision for specified flood return periods.

Channel Improvement & Lining

Widening, deepening, and lining of existing drainage channels using concrete, stone pitching, and vegetated linings to increase carrying capacity.

Road Drainage & Catch Basins

Design of road-side drains, kerb inlets, catch basins, and cross-drainage works to prevent road flooding and carriage-way damage.

Permeable Surfaces & Green Infrastructure

SuDS elements including permeable paving, bio-swales, rain gardens, and green roofs to reduce runoff at source in new and retrofit developments.

CODES & STANDARDS

Designed to Drainage & Hydrology Codes

Stormwater and flood-management infrastructure is designed to CPHEEO drainage manuals, IS hydrology codes, and recognised modelling standards.

Drainage & Stormwater Manuals
  • CPHEEO Manual — Storm water drainage systems
  • IRC:SP:50 — Urban drainage guidelines
  • IRC:SP:42 — Road drainage practice
  • IS 9542 — Surface drains practice
  • CWC Guidelines — Urban flood management
  • NDMA Guidelines — Urban flooding
Hydrology & Design Codes
  • IS 5477 — Reservoir storage capacity
  • IS 4987 — Recording rain-gauge practice
  • IS 1192 — Velocity-area discharge method
  • CWC IDF Curves — Rainfall intensity-duration
  • IMD Data Norms — Design rainfall analysis
  • Rational / SCS — Runoff estimation methods
Structural & Material Codes
  • IS 456 — Plain & reinforced concrete
  • IS 458 — Precast concrete pipes
  • IS 4111 — Ancillary drainage structures
  • IS 875 — Design loads
  • IRC:SP:13 — Small bridges & culverts
  • IS 3370 — Retention / detention tanks
Hydrological modelling, drainage network design, and structural detailing follow the latest revisions of the above codes and manuals, alongside relevant municipal / urban-local-body drainage standards and project-specific design storms.

Facing Flooding or Drainage Challenges?

Our flood and stormwater engineers can assess your catchment, model flood scenarios, and design cost-effective mitigation solutions.

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