Stormwater Design Engineer in Fullerton CA: Complete 2025 Guide

Stormwater design engineering is a critical component of development projects in Fullerton, CA, where strict regulations protect water quality in the Santa Ana River watershed. Whether you're planning a commercial development in downtown Fullerton, a residential subdivision near the Fullerton Arboretum, or an industrial facility in the West Fullerton area, understanding stormwater design requirements is essential for project approval and environmental compliance.

Introduction: Why Stormwater Engineering Matters in Fullerton

**Stormwater design engineering involves creating systems to manage rainfall runoff, prevent flooding, protect water quality, and comply with state and local regulations.** In Fullerton, these requirements are particularly stringent due to the city's location in the heavily regulated Santa Ana River watershed.

What makes Fullerton stormwater engineering unique:

**Regional Water Quality Control Board oversight:** Enforces California's statewater quality regulations
**Orange County drainage requirements:** County-wide standards in addition to city requirements
**Historic flooding areas:** Parts of Fullerton require enhanced drainage design
**Mixed development:** From dense downtown to suburban residential, each requires different approaches
**Established infrastructure:** Working with older stormwater systems requires careful analysis

Key regulatory drivers:

1. **National Pollutant Discharge Elimination System (NPDES)** - Federal program regulating stormwater discharges 2. **California Stormwater Quality Association (CASQA)** - State-level best management practices 3. **Santa Ana Regional Water Quality Control Board** - Local enforcement and oversight 4. **Fullerton Municipal Code Chapter 15** - City-specific drainage and stormwater requirements 5. **Orange County Drainage Area Management Plan (DAMP)** - County-wide stormwater management

What this guide covers:

1. Understanding stormwater engineering and regulations 2. Fullerton-specific requirements and permits 3. Low Impact Development (LID) and sustainable design 4. Water Quality Management Plan (WQMP) preparation 5. The stormwater design process 6. Costs and timelines for stormwater engineering 7. Choosing a qualified stormwater engineer

For related topics, see our guides on commercial building engineering, engineering design services, and sustainable design.

What is Stormwater Design Engineering?

**Stormwater design engineering is the specialized field of managing rainfall runoff to prevent flooding, erosion, and water pollution.** Engineers design systems to capture, treat, infiltrate, or safely discharge stormwater while meeting regulatory requirements.

Core Components of Stormwater Engineering

**1. Hydrology Analysis**

Rainfall data and design storm events (2-year, 10-year, 25-year, 100-year storms)
Watershed delineation and tributary area calculations
Time of concentration and runoff coefficient determination
Peak flow calculations using Rational Method or other approved methods
Pre-development vs post-development hydrologic analysis

**2. Hydraulic Design**

Pipe sizing and hydraulic grade line calculations
Storm drain system layout and design
Catch basin and inlet spacing and capacity
Energy dissipation structures
Open channel design (if applicable)
Pressure flow vs gravity flow analysis

**3. Water Quality Treatment**

Pollutant source identification
Treatment Best Management Practices (BMPs) selection
Sizing of bioretention areas, permeable pavement, vegetated swales
Treatment train approach for multi-BMP systems
Pollutant removal efficiency calculations
Long-term maintenance planning

**4. Low Impact Development (LID)**

On-site infiltration and retention
Minimizing impervious surfaces
Distributed treatment approach
Green infrastructure integration
Bioretention basins, rain gardens, permeable pavers
Harvest and reuse systems

**5. Erosion and Sediment Control**

Construction-phase erosion control plans
Temporary sediment basins and traps
Silt fences, fiber rolls, and inlet protection
Stabilization measures
SWPPP (Storm Water Pollution Prevention Plan) preparation

**6. Drainage System Design**

Surface drainage patterns and grading
Underground storm drain systems
Detention and retention basins
Pump stations (if required)
Overflow and emergency spillway design
Connection to existing city storm drain system

For comprehensive engineering services including stormwater design, see our structural engineering services and commercial engineering pages.

Fullerton Stormwater Regulations and Requirements

**Fullerton enforces multiple layers of stormwater regulations** from federal, state, regional, and local authorities.

Federal Requirements (NPDES)

**Clean Water Act Section 402:**

Regulates point-source discharges to waters of the United States
MS4 permit requires cities to regulate stormwater quality
Construction General Permit for projects disturbing 1+ acres
Industrial General Permit for certain facilities

**EPA Phase II Stormwater Regulations:**

Small MS4 requirements
Six minimum control measures for stormwater management
Public education and outreach
Illicit discharge detection and elimination
Construction site runoff control
Post-construction stormwater management
Pollution prevention/good housekeeping

State Requirements (California)

**State Water Resources Control Board:**

Statewide construction general permit (CGP)
Industrial general permit
Post-construction requirements for Priority Development Projects
Hydromodification management requirements

**California Stormwater Quality Association (CASQA):**

Best Management Practice (BMP) handbooks
Treatment BMP guidance
LID guidance documents
Model Water Quality Management Plan templates

Regional Requirements (Santa Ana RWQCB)

**Santa Ana Region MS4 Permit (Order R8-2010-0033):**

Applies to all development in Santa Ana River watershed (includes Fullerton)
Priority Development Project criteria
LID requirements for new development
Hydromodification management
Treatment control BMP performance standards
WQMP preparation and approval requirements

**Regional basin plan:**

Water quality objectives for Santa Ana River
Total Maximum Daily Load (TMDL) requirements
Beneficial uses protection

Orange County Requirements

**Orange County Drainage Area Management Plan (DAMP):**

Model WQMP template
Standard BMP selection and sizing procedures
Hydromodification management criteria
Unified approval process

**County of Orange Technical Guidance Document (TGD):**

Design standards for stormwater BMPs
LID BMP sizing procedures
Hydromodification analysis methods
Treatment BMP selection criteria

City of Fullerton Requirements

**Fullerton Municipal Code Chapter 15:**

Drainage design standards
Connection to city storm drain system
Stormwater quality requirements
Inspection and enforcement

**Fullerton Public Works Department - Engineering Division:**

Reviews all WQMP submittals
Approves connections to city storm drain
Enforces post-construction BMP maintenance
Issues grading and drainage permits

**Priority Development Project (PDP) triggers in Fullerton:**

New development creating 10,000+ sq ft of impervious area
Automotive service facilities
Restaurants (5,000+ sq ft or 25+ parking spaces)
Parking lots (5,000+ sq ft or 25+ spaces)
Hillside development (â‰¥5,000 sq ft disturbed area)
Industrial/commercial on known contaminated sites

If your project meets PDP criteria, a Water Quality Management Plan (WQMP) is required.

Low Impact Development (LID) in Fullerton

**Low Impact Development (LID) is the preferred approach for stormwater management in California,** emphasizing retention and infiltration of stormwater on-site using natural processes.

LID Principles

**Core concepts:** 1. **Minimize impervious area:** Reduce hardscape, use permeable alternatives 2. **Retain runoff on-site:** Infiltrate or evapotranspire stormwater where it falls 3. **Distributed treatment:** Multiple small BMPs throughout site vs single large facility 4. **Mimic natural hydrology:** Match pre-development hydrology to extent feasible 5. **Multifunctional landscape:** BMPs integrated into landscaping and site aesthetics

LID BMP Types

**Bioretention areas (rain gardens):**

Vegetated depressions with engineered soil media
Capture, infiltrate, and treat stormwater
Typically 4-6% of tributary impervious area
18-36" soil media depth
Underdrain system (if needed)
Plant selection for Orange County climate

**Permeable pavement:**

Allows infiltration through pavement surface
Types: permeable concrete, porous asphalt, permeable pavers
Suitable for parking lots, driveways, pedestrian areas
Requires aggregate base reservoir (12-24" typical)
May need underdrain if soils have low infiltration
Requires specialized maintenance

**Vegetated swales:**

Shallow vegetated channels
Convey and treat stormwater
Check dams to increase infiltration
Native or drought-tolerant vegetation
Integrated into landscape design

**Infiltration trenches/basins:**

Gravel-filled trenches or basins
Capture and infiltrate stormwater
Wrapped in filter fabric
Pre-treatment required
Not suitable for all soil types (infiltration testing required)

**Harvest and reuse systems:**

Cisterns or tanks capture runoff for irrigation
Reduces potable water demand
Credit toward LID requirements
Sized for irrigation demand vs storage capacity

**Green roofs:**

Vegetated roof systems
Reduce and slow runoff
Energy efficiency benefits
Higher cost, typically commercial applications

LID Feasibility in Fullerton

**Soil conditions:**

Much of Fullerton has moderately permeable soils (infiltration rate 0.5-2.0 in/hr)
Areas near Brea Creek may have poor drainage soils
Downtown areas may have compacted or contaminated soils from historic uses
Geotechnical investigation with infiltration testing required for LID feasibility

**Groundwater:**

Depth to groundwater typically 20-50+ feet in Fullerton
LID infiltration BMPs require 10 feet separation to seasonal high groundwater
Generally not a constraint in Fullerton

**Contamination concerns:**

Industrial areas (especially west Fullerton) may have soil/groundwater contamination
Infiltration not allowed on known contaminated sites
Vapor intrusion assessment may be required

**Space constraints:**

Downtown infill sites may have limited space for surface BMPs
Subsurface systems or off-site mitigation may be needed
Creative design integration required

For sustainable engineering approaches, see our sustainable design engineering guide.

Water Quality Management Plan (WQMP)

**A WQMP is a comprehensive plan for managing stormwater quality for Priority Development Projects.** It's required for project approval in Fullerton and throughout Orange County.

When is a WQMP Required?

Priority Development Project (PDP) categories:

1. **New development** creating 10,000+ sq ft impervious area 2. **Redevelopment** creating 5,000+ sq ft impervious area (if replacing 5,000+ sq ft existing) 3. **Automotive service facilities** (any size) 4. **Restaurants** (5,000+ sq ft or 25+ parking spaces) 5. **Hillside development** (disturbing â‰¥5,000 sq ft on 25%+ slope) 6. **Parking lots** (5,000+ sq ft or 25+ spaces, new or expanded) 7. **Retail gasoline outlets** (any size) 8. **Industrial facilities** (certain SIC codes, 10,000+ sq ft) 9. **Developments on contaminated sites** 10. **Mixed-use developments** triggering any PDP category

**Exemptions:**

Single-family homes on individual lots
Interior remodels with no exterior changes
Projects below thresholds

WQMP Components

Standard WQMP includes:

**1. Project Information**

Site address, assessor parcel numbers
Project description and site plan
Impervious area calculations
PDP category applicability

**2. Site Assessment**

Existing conditions (topography, drainage patterns, soils, vegetation)
Receiving water bodies
Potential pollutants of concern
Soil infiltration assessment
Geotechnical constraints

**3. Source Control BMPs**

Site design features to prevent pollution
Examples: proper trash enclosures, covered outdoor materials storage, designated wash areas
Education materials for tenants/occupants

**4. LID BMPs**

On-site retention through infiltration, evapotranspiration, harvest/reuse
Sizing calculations per Orange County TGD methodology
Maintenance requirements and responsible parties

**5. Treatment Control BMPs** (if LID alone insufficient)

Biotreatment, media filters, other treatment systems
Sizing calculations for water quality design flow
Expected pollutant removal efficiencies
Maintenance requirements

**6. Hydromodification Management** (if applicable)

For projects disturbing 1+ acre in susceptible downstream areas
Flow duration matching or detention/retention design
Continuous simulation modeling (SWMM, HSPF, etc.)

**7. BMP Maintenance Plan**

Maintenance tasks and frequencies for each BMP
Responsible party identification
Maintenance access provisions
Verification mechanism

**8. Drainage Plans**

Grading and drainage plan showing all BMPs
Tributary area delineation for each BMP
Stormwater conveyance system
Cross-sections and details for BMPs

**9. Calculations and Supporting Documentation**

Runoff calculations
BMP sizing calculations
Infiltration test results
Maintenance cost estimates

WQMP Review and Approval Process in Fullerton

**Step 1: Preliminary WQMP**

Submitted with initial entitlements (Conditional Use Permit, Site Plan Review, etc.)
Conceptual-level showing proposed BMP approach
City provides preliminary feedback

**Step 2: Final WQMP**

Submitted with building permit application
Detailed plans, calculations, maintenance agreements
City of Fullerton Engineering Division reviews
May require revisions (plan to allow 4-6 weeks)

**Step 3: WQMP Approval**

City issues approval letter
Becomes condition of building permit
Copy recorded with property deed

**Step 4: Construction**

BMPs installed per approved WQMP
City inspection during construction
Verification of installation prior to occupancy

**Step 5: Long-term Maintenance**

Property owner maintains BMPs per approved plan
Annual self-certification may be required
City spot-checks compliance
Penalties for non-compliance

For more on the permitting process, see our guide on building code compliance.

The Stormwater Design Process

**Typical stormwater engineering project timeline: 4-10 weeks for design,** depending on project size and complexity.

Phase 1: Project Kickoff and Site Assessment (Week 1)

**Initial engineer meeting:**

Review project plans (site plan, building elevations, landscape plan)
Discuss project type, size, PDP applicability
Review available site information (soils, topography, existing drainage)
Identify potential constraints (contamination, poor soils, tight site)

**Site reconnaissance:**

Visit project site
Observe existing drainage patterns
Identify connection points to city storm drain
Document existing conditions

**Data collection:**

Topographic survey (if not already available)
Geotechnical report review
City storm drain records and as-builts
Regional drainage studies

**Deliverables:**

Scope confirmation
Project schedule
Request for any additional information needed

Phase 2: Preliminary Design and BMP Selection (Week 2-3)

**Hydrologic analysis:**

Delineate tributary drainage areas
Calculate pre-development vs post-development runoff
Determine design storm parameters
Identify receiving water and discharge point

**BMP feasibility assessment:**

Evaluate LID feasibility based on soils, space, groundwater
Screen BMP alternatives
Develop preliminary BMP layout
Size BMPs per Orange County TGD

**Preliminary WQMP preparation** (if required):

Draft WQMP document
Conceptual plans showing BMP locations
Source control checklist
Preliminary maintenance plan

**Engineer deliverables:**

Preliminary drainage plan
WQMP (preliminary or final, depending on permit timing)
Cost estimate for BMP construction

Phase 3: Detailed Design (Week 4-6)

**Detailed BMP design:**

Finalize BMP sizing calculations
Prepare detailed grading and drainage plans
Design BMP cross-sections and details
Specify materials and construction methods

**Storm drain system design:**

Size pipes, inlets, manholes
Calculate hydraulic grade lines
Design energy dissipation
Connection to city system design

**Plan set preparation:**

Title sheet with project information
Existing conditions plan
Demolition plan (if applicable)
Grading and drainage plan
BMP details and cross-sections
Erosion control plan (SWPPP if required)
Notes and specifications

**WQMP finalization:**

Complete all required sections
Include all calculations and supporting documentation
Prepare exhibits (drainage plans, BMP details)
Maintenance plan and agreement

**Engineer deliverables:**

Complete plan set
Final WQMP document
Drainage study/report
Engineer's cost estimate

Phase 4: Plan Check and Approvals (Week 7-10)

**Submittal to City of Fullerton:**

Engineering Division reviews WQMP
Public Works reviews drainage plans
Building & Safety reviews overall project

**Plan check process:**

Initial review: 2-4 weeks typical
Corrections issued (expect some on first submittal)
Engineer addresses corrections
Resubmittal and re-review: 1-2 weeks
Approval (may require 2-3 cycles)

**Common corrections:**

BMP sizing calculation clarifications
Maintenance access provisions
Source control BMP additions
Plan detail clarifications
Connection to city storm drain verification

**Final approval:**

WQMP approval letter from City
Building permit issuance
Grading permit issuance (if applicable)

Phase 5: Construction Support (Duration varies)

**Pre-construction meeting:**

Review WQMP requirements with contractor
Discuss inspection requirements
Clarify construction sequencing

**Construction phase services:**

Respond to contractor RFIs
Review shop drawings and submittals
Site visits to verify installation
Address field conditions

**Final verification:**

As-built documentation
BMP installation verification
Final inspection by City
Occupancy clearance

For more on working with engineers, see our guide to hiring a structural engineer (similar considerations apply to stormwater engineers).

Costs for Stormwater Engineering in Fullerton

Stormwater design engineering fees: $4,000-$20,000+ depending on project size and complexity.

Engineering Fees

**Small projects (residential, small commercial):**

WQMP only: $3,000-$5,000
WQMP + drainage plans: $5,000-$8,000
Includes: site assessment, BMP design, WQMP document, plan check response

**Medium projects (commercial, multi-family):**

Standard WQMP and drainage: $8,000-$15,000
With complex BMPs or site constraints: $12,000-$20,000
Includes: full drainage design, storm drain system, WQMP, calculations

**Large projects (industrial, major commercial):**

Comprehensive stormwater design: $20,000-$50,000+
May include hydromodification analysis, advanced modeling
Detention basin design, pump stations, etc.

**Additional services:**

Geotechnical investigation with infiltration testing: $2,500-$5,000
Hydromodification analysis (continuous simulation modeling): $5,000-$15,000
SWPPP preparation: $2,000-$5,000
Construction phase services: $150-$250/hour or lump sum
WQMP revisions after initial approval: $1,000-$3,000

BMP Construction Costs

**LID BMPs:**

Bioretention areas: $15-$30 per sq ft
Permeable pavement: $8-$20 per sq ft (vs $3-$8 for conventional pavement)
Vegetated swales: $20-$50 per linear foot
Infiltration trenches: $50-$100 per linear foot

**Treatment control BMPs:**

Proprietary treatment systems: $5,000-$50,000 depending on size
Sand filters: $10,000-$30,000
Detention basins: Highly variable, $20,000-$200,000+

**Storm drain systems:**

Storm drain pipes: $100-$250 per linear foot (varies by size)
Catch basins/inlets: $2,000-$5,000 each
Manholes: $4,000-$8,000 each

**Total project costs:**

Residential addition/ADU: $5,000-$15,000 (engineering + BMPs)
Small commercial: $15,000-$40,000
Medium commercial: $40,000-$100,000
Large commercial/industrial: $100,000-$500,000+

For detailed engineering cost information, see our structural engineer cost guide (similar factors affect stormwater engineering costs).

Choosing a Stormwater Design Engineer in Fullerton

Select an engineer with stormwater expertise, Orange County regulatory experience, and Fullerton project experience.

Essential Qualifications

**Professional licensing:**

California-licensed Civil Engineer
Verify license at bpelsg.ca.gov
QSD (Qualified SWPPP Developer) certification (if SWPPP needed)
QSP (Qualified SWPPP Practitioner) certification (if construction inspection needed)

**Stormwater expertise:**

Minimum 5+ years stormwater design experience
Orange County DAMP experience
Santa Ana Region MS4 permit knowledge
LID BMP design experience
Hydromodification analysis capability (if needed)

**Fullerton experience:**

Portfolio of approved WQMPs in Fullerton
Relationship with City of Fullerton Engineering staff
Knowledge of local drainage conditions
Familiarity with Fullerton plan check process

**Software capabilities:**

AutoCAD Civil 3D for grading and drainage plans
Hydrology/hydraulics software (HydroCAD, StormCAD, etc.)
Continuous simulation modeling (if hydromod required)
BMP sizing tools

Evaluating Engineers

**Interview questions:** 1. How many WQMPs have you prepared for projects in Fullerton? 2. What's your experience with [specific BMP type needed]? 3. Have you designed similar projects (size, type)? 4. What's your typical timeline and process? 5. How do you handle plan check corrections? 6. Do you provide construction phase services? 7. What's included in your fee, and what costs extra? 8. Can you provide references from recent Fullerton clients? 9. Are you familiar with Orange County TGD procedures? 10. What's your plan check approval rate?

**Red flags:**

No Orange County WQMP experience
Unfamiliar with LID requirements
Significantly lower fees than other qualified engineers (may indicate inexperience)
Poor communication or responsiveness
No Fullerton project examples
Cannot explain regulatory requirements

**Green flags:**

10+ WQMPs approved in Orange County
Multiple Fullerton projects successfully permitted
QSD/QSP certifications
Clear, detailed proposal
Proactive recommendations
Good rapport with City staff
Strong references

For more guidance on selecting engineers, see our article on choosing an engineering design firm.

Frequently Asked Questions

Q: Do I need a stormwater engineer for my Fullerton project?

A: If your project is a Priority Development Project (PDP), yes. PDPs include new development creating 10,000+ sq ft impervious area, automotive facilities, restaurants 5,000+ sq ft, parking lots 5,000+ sq ft, and other categories. A licensed civil engineer must prepare your WQMP.

Q: How much does a WQMP cost in Fullerton?

A: Typical range $3,000-$15,000 depending on project size and complexity. Simple commercial projects may be $5,000-$8,000. Complex projects with hydromodification or challenging sites may be $15,000-$30,000+.

Q: How long does WQMP approval take?

A: Engineering design typically takes 4-6 weeks. City review takes 2-4 weeks initially, then 1-2 weeks per revision cycle. Total time from starting engineering to WQMP approval: 8-12 weeks typical. Plan for potential delays.

Q: What are Low Impact Development (LID) BMPs?

A: LID BMPs retain and treat stormwater on-site using natural processes. Examples: bioretention areas (rain gardens), permeable pavement, vegetated swales, infiltration trenches, cisterns. LID is required for all PDPs in California unless infeasible.

Q: What is hydromodification and do I need analysis?

A: Hydromodification is the alteration of natural flow patterns that can cause downstream erosion. Projects disturbing 1+ acre in susceptible downstream areas require hydromodification management. Requires continuous simulation modeling and flow duration matching.

Q: Can I use a treatment system instead of LID?

A: Only if LID is infeasible due to documented site constraints (e.g., contaminated soils prohibiting infiltration, poor soil infiltration, shallow groundwater, tight site with no space). LID must be maximized to extent feasible before treatment-only BMPs.

Q: Who maintains stormwater BMPs after construction?

A: Property owner is responsible for long-term BMP maintenance per approved WQMP. Maintenance requirements are recorded with property deed. City inspects periodically and can enforce maintenance requirements.

Q: What are source control BMPs?

A: Site design features and operational practices that prevent pollutants from contacting stormwater. Examples: covered trash enclosures, designated wash areas, landscaping with minimal pesticides/fertilizers, education for occupants. Required for all PDPs.

Q: Do I need a geotechnical investigation for stormwater design?

A: Highly recommended, and often required for LID feasibility assessment. Infiltration testing determines if bioretention and other infiltration BMPs are feasible. Cost: $2,500-$5,000 typical.

Q: Can I connect to the city storm drain system?

A: Yes, but requires City of Fullerton approval. Must show adequate capacity in existing system, provide water quality treatment, and pay any required fees. Engineer coordinates connection design and approval.

Q: What's the difference between WQMP and SWPPP?

A: WQMP addresses permanent, post-construction stormwater management. SWPPP addresses temporary, construction-phase erosion and sediment control. Projects disturbing 1+ acre require both. Projects under 1 acre may require WQMP only (if PDP).

Q: What happens if I don't comply with my WQMP?

A: Non-compliance can result in penalties from City of Fullerton and/or Regional Water Board. Fines range from $1,000/day to $25,000+/day for serious violations. City can also red-tag property and require corrective action.

Related Resources

For location-specific engineering guidance, visit our city pages for Irvine, Anaheim, Orange, Newport Beach, Huntington Beach, Costa Mesa, and Mission Viejo.

**Ready to discuss your Fullerton stormwater project? Contact AAA Engineering Design at (949) 981-4448.** Our California-licensed Civil Engineers bring deep stormwater expertise, Orange County regulatory knowledge, and proven results to every project throughout Fullerton and North Orange County.