The document discusses California's efforts to regulate stormwater runoff from new construction projects using a watershed management approach. It acknowledges the challenges of population growth putting pressure on water resources. Low impact development techniques are promoted to mimic natural hydrologic processes and protect water quality. However, over-engineered solutions risk overlooking soils and overall watershed health. The regulatory framework is continuing to evolve from a focus on runoff volume to consideration of additional hydrologic factors and outcomes related to beneficial uses.

1. Pimples to Dimples
A regulatory perspective on our efforts to control
runoff from new construction in CA.
Greg Gearheart, PE
Storm Water Program / SWRCB

2. I wish to acknowledge the hard work of my
colleagues at the State Water Board in helping
gather information used in this presentation:
• Eric Berntsen, PH, CFM, CPESC, CPSWQ
• Bill Hereth
• Laurel Warddrip

4. Dimples

7. Regulating Symptoms vs. Causes

8. The Tail (of the Dragon)
• The mission of the Water Boards is to
preserve and enhance the quality of
CA’s water resources, and ensure their
proper allocation and efficient use for
the benefit of present and future
generations.

9. Millions of Californians
1980 – 23.7 million
2005 – 37 million
2020 – 50 million (projected)
Where do we put everyone?
“The Californians”-
SNL & Tumblr.com

11. Hydrologic Cycle
From Lake (2004)

13. Exurbanization
in the Sierra
Foothills
from “New Geographies
of the American West”
by William Travis

14. Relict F
Abandoned
Active
Relict Fan

15. Native Soil
From King County

16. Disturbed Soil
From King County

18. Oki 2009

19. From NOAA
Lawn is the largest irrigated
“crop” in the US

21. Sources of Impairment (USEPA 2006)

23. New Construction Numbers
• In FY 2008-2009:
~ 17,000 enrollees in our construction permit
~ 3,000 new enrollees
• FY 2009-2010:
–~10,000 enrollees/facilities
–~150 new enrollees per month
–~50 acres per facility = ~500,000 acres
• Today: ~5000 (new permit + economy)

24. 1950's – Sacramento Area
2000's – Sacramento Area

25. Driven by maintenance interests...

27. Water Boards nuts and bolts
Our regulatory actions (e.g., CWA401 Certs,
WDRs, NPDES Permits, enforcement, etc.)
require discharges to be protective of our water
quality standards (WQS):
– Water quality standard = beneficial uses + objectives
– Water Boards may “choose to prevent any
degradation”

28. CWA - Water Quality
Standards
• Water Quality Standards are made up of:
– Beneficial Uses (designated to specific
waterbodies), plus
– water quality criteria; and
– an antidegradation policy.
• Beneficial Uses (BUs) are:
• often not directly related to key water resource
uses valued by communities (it might take a suite
of them to protect wetlands and streams, for
example)

29. Beneficial Uses Used to
Protect California Wetlands &
Streams
• AGR – Agricultural Supply
• FLD – Flood Peak
Attenuation/Flood Water
Storage
• FRSH – Freshwater
Replenishment
• GWR – Groundwater
Recharge
• MAR – Marine Habitat
• MUN – Municipal and
Domestic Supply
• RARE – Preservation of Rare
and Endangered Species
• REC-1 – Water Contact
Recreation
• REC-2 – Non-Water Contact
Recreation
• SHELL – Shellfish Harvesting
• SPAWN – Fish Spawning
• WARM – Warm Freshwater
Habitat
• WILD – Wildlife Habitat
• WQE – Water Quality
Enhancement

30. Functional Framework:
Regulatory Tools
•
Landscape (laparoscopic?) and
watershed tools:
– Storm Water NPDES Permits
– CEQA ?
•
Waterbody tools:
– CWA 401 Certifications / Wetland program
•
Project tools:
– Construction permit, CEQA, local
ordinances, building code?

31. Clean Water Act Permits
• CWA Section 402 – Point Sources
– The National Pollutant Discharge Elimination
System (NPDES) – applies to all point sources
of pollutants
– Storm water outfalls are considered “point
sources” and these regulations apply to:
• Industrial Sources (including Construction Activities)
– BAT/BCT standard applies
• Municipal Sources (large and small communities)
– MEP standard applies

32. MS4s and MEP
•
Municipal Separate Storm Sewer System
(MS4)
– Local governments, Caltrans, and some
“non-traditionals” in Phase II
•
Maximum Extent Practicable (MEP)
– MS4s must reduce pollutants in their effluent
to the MEP
– A hybrid standard – part performance-based
and level of effort ($)

33. MS4
Water Quality
Standards (WQS) apply
to receiving waters.
MS4 Permits are
supposed to ensure WQS
are met via MEP
standard applied at “ends
of pipes.”
LID

34. MS4 requires project to
use LID to reduce
pollutants to MEP to
protect
WQS
WQS MEP
Receiving Water
Limitations
Effluent Limitations
MS4 LID
Permittee Desired Practice
(applied to project)

35. Enforcing Post-
construction Standards
via MS4 Permits
•
City Y has an MS4 Permit that requires
all projects adding over 10,000 square
feet of impervious area, etc., to do LID to
meet the 5% EIA standard
•
Project X in City Y fails to comply (or
worse, fakes compliance)
•
Project X is built w/o compliance → City
Y is in violation
•
State/EPA must enforce against City Y

36. NPDES Permit Drivers
towards LID
•
1990's – MS4s had to have post-
construction elements in their plans
•
~2000 – MS4s had to have Standard
Urban Stormwater Management Plans
(SUSMPs)
– capture/treat 85 %ile, 24-hr runoff event
– often resulted in regional basins
– difficult to enforce

37. Modern MS4 Tools
• SUSMPs (the plan, not necessarily the
standard)
• Hydromodification Management Plans
(HMPs)
• Low Impact Development
• Additional post-construction elements
(e.g., water quality BMPs)

38. Common Triggers for
Projects Required to do
LID, etc.
•
>10,000 square feet of impervious
•
“Priority projects” - varies statewide
•
Older permits may trigger at 20,000
square feet
•
other thresholds

39. Common Project
Outcomes
•
Older permits
– Large vaults, structural devices
– Detention basins
– Capture/treat approach
•
Newer permits
– LID
– Flow duration control
– Hydromod/instream intervention in some
cases

41. Common Performance
Criteria
•
Criteria (varies)
– “Post equals pre-development” runoff
volume
– Ranges of flows to control
– (Effective) Impervious area threshold(s)
•
Method of analysis/calculation (varies)
– Continuous simulation
– Rational (modified) method
– Not specified

42. Specific LID
Requirements
•
Construction General Permit requires
“post equals pre” and uses LID-esque
runoff credits (trees, cisterns, etc.)
•
LID Manuals (some developed, some in
progress)
•
Vague “LID preferential” language in
some cases
•
Some MS4 permits contain no LID
language

44. Subdivision Example

45. Pre-
Development
(Pre-Project)
Post-
Development
(5% EIA)
Post-
Development
(1% EIA)
Percent EIA 0 5 1
Precipitation
(inch)
0.75 0.75 0.75
Runoff (inch) 0.002 0.04 0.007
Project Area
(acres)
10 10 10
Runoff (acre-ft) 0.002 0.03 0.006
% Increase over
Pre-Development
N/A 1,500 300
Subdivision Example

46. Effective Impervious Area
(EIA)
•
Concerns over using EIA as a surrogate for
hydrologic performance
•
Treats the symptom (surface), not the cause
(hydrology) of WQS impacts
•
Could be gamed (the “grassy moat” scenario)
•
Should use Runoff Volume, Time of
Concentration, and other appropriate
hydrologic metrics instead

47. The importance of soil
• Healthy soils are critical to watershed
health and function
• Engineers tend to focus on the plumbing
more than the soils and biotic features
• Infiltration and recharge do not always
work – LID is flexible, why aren't we?

48. Native Soil
From King County

49. Disturbed Soil
From King County

50. From Soil Food Web, Inc

51. State Water Board’s Watershed
Management Initiative (1996)
“water quality and ecosystem problems are best
prioritized, addressed, and solved at the local
watershed level rather than at the individual
discharger, waterbody, or state agency level……”

54. Watershed Management Zones
•Allow us to identify the most appropriate
criteria to protect dominant watershed
processes.
• Examples: No channel protection criteria in
subwatersheds without streams
• Prescribe higher infiltration volume for areas
that can handle it
• Limit development on areas that supply coarse
sediment

55. Social well-being
Sustainability
Personal Health
Leadership &
demonstration
Efficiency ethic
Environmental
awareness
Minimal impact
Public
acceptance &
demand
Product &
service
availability
Professional
competency
StewardshipStewardship
Reduce Runoff
Soil Conservation & Health
Water Quality
Habitat
Urban environment
Water
Energy
Air (carbon / GHG)
Biomass (green waste reduction)
Resource
Efficiency &
Protection
Watershed
Efficiency &
Protection
Market
Transformation
Market
Transformation
Quality of LifeQuality of Life
Watershed Approach – The New Norm (CA
Urban Water Conservation Council)

57. BUILD “LIVING SOIL”
• Healthy soil biology, full of micro-
organisms forms the foundation
for the entire site ecology
• Similar to the role of plankton in
the ocean
· Creates soil structure
· Stores and cycles nutrients · protect plants from pests
· Improves water infiltration and storage
· Filters out urban pollutants

59. UTILIZE MULCH
• Apply minimum 2” layer mulch
over all planting beds
• Utilize local, recycled, organic
mulch from tree trimmings
• Avoid forest product mulches
• Reapply as needed
• Keep away from root crowns and
trunks

66. From Eric’s
Front Yard

67. From Ann Riley

69. Risks of over-engineered
LID
•
Engineered boxes often require
engineered soils
•
Devices buried in corners of commercial
lots
•
Site runoff performance may meet goals,
but overall watershed goals and
sustainability of project is questionable

70. Challenges Ahead for LID
•
Regulating LID
– Retrofits, hydrologic criteria, performance
measurement, over-engineering,
enforcement, linking to WQS and outcomes
•
Legislating LID
– Diverse interests, oversimplification of CA
hydrology, promises of global savior
•
Mother Nature

71. Sustainability Tests
• Resource – protection to enhancement and
reuse (“runoff is a resource”)
• Technical – complex, technological
standard-based to simple, natural,
performance-based solutions
• Institutional – centralized, subsidized
approaches to decentralized, self-supporting
approaches
• Community – healthy individual, societal
cost driven equations to healthy community,
community opportunity equations

72. My Recommendations
•
Water Board/USEPA should develop numeric criteria and
objectives that address hydromod impacts using LID,
instream, and other techniques – in support of beneficial
uses and WQS
•
Wherever feasible, directly regulate those responsible for
constructing projects (and maintaining BMPs), discharging
storm water
•
Open source model → performance-based standards with
flexibility to adapt/learn
•
Promote sustainable approaches to water management
wherever feasible (soils, irrigation, gray water, everything)

73. Greg Gearheart | 916-341-5892 | ggearheart@waterboards.ca.gov