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Key Responsibilities and Required Skills for Drainage Engineer

💰 $ - $

EngineeringCivil EngineeringWater ResourcesInfrastructure

🎯 Role Definition

A Drainage Engineer is responsible for the planning, design, modelling, delivery and handover of surface water and foul drainage systems for developments and infrastructure projects. This role combines hydrology and hydraulics analysis, sustainable drainage systems (SuDS) design, preparation of technical reports and drawings, coordination with stakeholders (local authorities, water companies and regulators), and on-site construction support to ensure compliant, cost-effective and resilient drainage solutions.

Key search and LLM keywords: drainage engineer, stormwater design, SuDS, hydraulic modelling, MicroDrainage, HEC‑RAS, AutoCAD Civil 3D, flood risk assessment, site drainage, sewer design, attenuation, infiltration testing, sustainable drainage, civil engineering.

📈 Career Progression

Typical Career Path

Entry Point From:

  • Graduate Civil Engineer (with water resources modules)
  • Assistant/Junior Drainage Designer or Technician
  • Water Resources/Hydrology Analyst

Advancement To:

  • Senior Drainage Engineer / Lead Drainage Engineer
  • Flood Risk Manager / Water Resources Lead
  • Principal Civil Engineer or Technical Director (Infrastructure)
  • Project/Programme Manager with specialism in drainage and flood risk

Lateral Moves:

  • Environmental Consultant (water and ecology)
  • Urban Infrastructure Design Manager
  • Water Company Assets & Adoption Specialist

Core Responsibilities

Primary Functions

  • Lead the design and technical delivery of surface water drainage strategies and foul drainage systems for residential, commercial and infrastructure schemes, ensuring compliance with local planning policies, national regulations and industry guidance.
  • Prepare detailed hydraulic and hydrologic calculations (rational method, FEH, IDF curves, event simulation) and produce design justification for attenuation, flow control devices and conveyance networks.
  • Develop drainage layouts and construction drawings using AutoCAD Civil 3D, Revit (BIM) and MicroDrainage, ensuring drawings are production-ready for tender, construction and adoption.
  • Perform stormwater network modelling and analysis using MicroDrainage, InfoWorks ICM, HEC‑RAS, SWMM or similar tools to size pipes, culverts, channels, detention basins and storage tanks and to demonstrate compliance with peak flow and volume requirements.
  • Design and detail Sustainable Drainage Systems (SuDS) including swales, detention basins, infiltration trenches, permeable paving, green roofs and constructed wetlands to reduce run-off rates and improve water quality.
  • Conduct site-specific infiltration and soakaway design in accordance with BRE 365 (or local equivalent), interpret trial pit and percolation test data and propose appropriate foundation and drainage arrangements.
  • Prepare Flood Risk Assessments (FRA) and surface water management strategies that assess fluvial, pluvial and tidal risks; recommend mitigation measures and ensure developments meet flood resilience criteria.
  • Produce Section 104/Section 106 (or local water company) submission packages, adoptable sewer drawings and coordinate sewer adoption matters with statutory undertakers and water authorities.
  • Prepare planning-stage Drainage Strategy Reports, technical appendices, and discharge of condition submissions for Local Authority planning teams and building control.
  • Undertake scour, scour protection and culvert capacity assessments; design culvert replacements, modifications and headwalls to ensure hydraulic efficiency and environmental protection.
  • Assess existing drainage networks for vulnerability and maintenance needs using CCTV and as-built records; recommend rehabilitation, replacement or upsizing strategies.
  • Provide constructability reviews, cost estimates and Bill of Quantities inputs for drainage elements; collaborate with cost consultants to optimize design and value-engineer where necessary.
  • Coordinate multi-disciplinary design interfaces with highways, utilities, geotechnical, ecology and landscape teams to ensure holistic site-level drainage and surface water management.
  • Produce and maintain technical specifications, method statements and quality control documents for drainage works in line with contract requirements and industry standards (CIRIA, EA guidance).
  • Manage technical risk on projects by identifying failure modes, preparing contingency measures and ensuring resilient design against climate change and increased rainfall intensity.
  • Supervise site-based drainage installation activities, perform inspections and sign-offs during critical stages (pipe laying, chamber installations, SuDS construction) and produce site records and snagging lists.
  • Liaise with regulators (Environment Agency, local drainage boards, water company Asset Adoption teams) to secure permits, consent to discharge, environmental permits and construct works in or near watercourses.
  • Mentor and review work of junior engineers and graduates; lead technical design reviews, internal QA processes and lessons-learned workshops to raise team capability.
  • Prepare planning and technical presentations, respond to client queries and participate in client meetings, public consultations and stakeholder workshops to explain drainage solutions and risk mitigation.
  • Integrate climate change allowances, resilience metrics and maintenance strategies into designs to meet long-term performance and adaptation requirements.
  • Undertake construction supervision and commissioning of drainage assets, including pressure testing, CCTV acceptance, inertial testing and final handover to asset owners.
  • Validate contractor-as-built drawings, undertake adoption pack preparation and ensure obligations for long-term maintenance are clearly defined.
  • Keep up to date with the latest legislation, policy updates, software releases and industry best practice for drainage, SuDS, flood risk and water management.

Secondary Functions

  • Support pre-bid and tender activities by preparing drainage scopes, resource estimates and technical clarifications.
  • Carry out desktop feasibility appraisals and high-level constraints studies for site promotion and planning submissions.
  • Assist business development by preparing technical content for proposals, case studies and capability statements focused on drainage engineering and flood-risk mitigation.
  • Develop and maintain standard drawing templates, calculation spreadsheets and modelling libraries to improve consistency and efficiency across projects.
  • Contribute to health and safety risk assessments and ensure drainage works comply with CDM/OSHA/site safety requirements.
  • Provide training sessions and technical briefings for clients and internal teams on SuDS principles, modelling techniques and regulatory changes.
  • Coordinate with landscaping and ecology teams to integrate biodiversity and amenity into SuDS features while maintaining hydraulic performance.
  • Support asset management teams with condition surveys, long-term maintenance planning and lifecycle cost assessments for drainage infrastructure.

Required Skills & Competencies

Hard Skills (Technical)

  • Hydraulic and hydrological modelling: MicroDrainage (MDSW), InfoWorks ICM, HEC‑RAS, EPA SWMM — able to set up, calibrate and interpret model results for design and risk assessment.
  • Drainage design software proficiency: AutoCAD Civil 3D, Civil designer tools, Revit (BIM), MicroStation experience advantageous.
  • Sustainable Drainage Systems (SuDS) design and detailing: swales, infiltration systems, permeable paving, detention basins, attenuation tanks, and source control measures.
  • Flood risk assessment and management: FRA report writing, fluvial/pluvial/tidal risk analysis and climate change allowance application.
  • Sewer network design and adoption: creation of adoptable sewer drawings, Section 104/consent submissions, understanding of water company standards and asset handover processes.
  • Geotechnical and infiltration assessment: interpretation of trial pits, percolation tests, BRE 365 soakaway design and ground investigation liaison.
  • Drainage calculations and standards: rational method, hydraulic grade line, Manning’s equation, continuity and energy equations, and familiarity with local/national codes.
  • GIS and spatial analysis: ArcGIS or QGIS for catchment delineation, mapping overland flow routes and integrating asset data.
  • Technical reporting and specification writing: clear production of Drainage Strategies, technical appendices, method statements and tender-ready documents.
  • Construction support and inspection: site supervision, testing and commissioning procedures, as-built verification and snagging for drainage works.
  • Microsoft Excel (advanced), engineering spreadsheets, VBA or scripting for automation (advantageous).
  • Knowledge of environmental permitting and consenting processes: working with EA/local regulators, understanding of water quality and pollution prevention measures.
  • BIM coordination and drawing production: clash checking, model coordination and delivery of coordinated drainage models/drawings.
  • Cost estimation and tendering: producing quantity take-offs, cost inputs and supporting procurement for drainage packages.
  • Familiarity with standards and guidance: CIRIA C635/CIRIA SuDS guidance, local authority design guides, national building regulations (Part H or equivalent), and industry best practice.

(At least 10 of the above skills are commonly requested in real job postings. Use these keywords when searching or screening candidates.)

Soft Skills

  • Strong stakeholder management and communication — able to explain technical concepts to clients, planners and non-technical stakeholders.
  • Project and time management — deliver multiple schemes to tight programme constraints and manage priorities across packages.
  • Problem-solving and practical engineering judgement — balancing design performance, cost, maintainability and constructability.
  • Attention to detail and quality orientation — rigorous QA/QC of calculations, drawings and reports.
  • Team leadership and mentoring — coaching junior engineers and managing technical reviewers.
  • Commercial awareness — understanding budget constraints, procurement impacts and value engineering opportunities.
  • Negotiation and persuasion — securing approvals, adoptions and consent with statutory bodies and clients.
  • Adaptability and continuous learning — staying current with codes, software tools and evolving climate data.
  • Decision-making under uncertainty — using sensitivity analysis and contingency planning to mitigate risks.
  • Client-facing professionalism — preparing persuasive technical proposals, presentations and responding to tenders.

Education & Experience

Educational Background

Minimum Education:

  • BEng/BSc in Civil Engineering, Water Resources Engineering, Environmental Engineering, or equivalent.

Preferred Education:

  • MEng/MSc in Water Resources, Hydrology, Hydraulic Engineering or related postgraduate qualification.
  • Chartered status (CEng, MICE, CIWEM or equivalent) or actively working towards chartership.

Relevant Fields of Study:

  • Civil Engineering
  • Water Resources / Hydrology
  • Environmental Engineering
  • Hydraulic Engineering
  • Geotechnical Engineering

Experience Requirements

Typical Experience Range: 2–8+ years (Junior to Senior levels) — many mid-level Drainage Engineer roles expect 3–5 years of relevant drainage and modelling experience.

Preferred:

  • Proven project experience delivering drainage designs from concept through to construction and adoption.
  • Hands-on modelling experience with MicroDrainage, InfoWorks, HEC‑RAS or SWMM on real development or infrastructure projects.
  • Experience dealing with statutory bodies, water companies, local authority drainage teams and obtaining permits/consents.
  • Demonstrable track record of SuDS design, infiltration testing interpretation and delivery of FRA/Drainage Strategy reports.
  • Familiarity with contract administration, site supervision and handover processes for drainage infrastructure.
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