ITS TIME TO GET YOUR MIND IN THE GUTTER_

							IT’S TIME TO GET YOUR
 MIND IN THE GUTTER!
 Overview of Proposed Coastal
      Stormwater Rules
        February 14, 2008
 Rules Affect ALL Land in Twenty
Coastal Counties With Disturbance
   Greater Than 10,000 Sq. Ft.

Beaufort, Bertie, Camden, Carteret,
 Chowan, Craven, Currituck, Dare, Gates,
 Hertford, Hyde, Pamlico, Pasquotank,
 Pender, Perquimans, Tyrrell, Washington
AND Phase II Counties - Brunswick, New
 Hanover and Onslow.
Understanding the Rules:
Definition of Terms
• Land Disturbing Activity
• Built-Upon Area
• Lot Coverage
• Vegetative Buffer
• SA Waters
Land Disturbing Activity


DWQ Definition:
Any use of the land that results in a change
 in the natural cover or topography that
 may cause or contribute to sedimentation.
Built-Upon Area (BUA)
That portion of a project that is covered by impervious or
  partially impervious surface including, but not limited to,
  buildings; pavement and gravel areas such as roads,
  parking lots, and paths; and recreation facilities such as
  tennis courts.

Does not include a wooden slatted deck, the water area of
  a swimming pool, or pervious or partially pervious paving
  material to the extent that the paving material absorbs
  water or allows water to infiltrate through the paving
  material. Septic systems/drain fields are not impervious
  surfaces.
BUA – How is it measured?
• Built-upon area is a measure of the hard surfaces or
  impervious cover for a site. For each piece of land,
  divide the amount (area) of impervious surface
  (i.e.: structures, roads, parking lots) located on-site by
  the total land area under consideration. Multiply the
  resulting fraction by 100 to get the percent built-upon
  area.

• If disturbing more than one acre of land for residential
  development, or 10,000 sq. ft. for non-residential
  development, wetlands cannot be included in total land
  area under consideration.
Lot Coverage

• Defined by each municipality and County.
• Do not confuse with Built-Upon Area.
• Prior built-upon area low density
 thresholds (25%/30%) may have been
 more flexible than local lot coverage
 allowance.
Vegetated Buffer
• "Vegetative Buffer" means an area of natural or
  established vegetation directly adjacent to surface
  waters through which stormwater runoff flows in a
  diffuse manner to protect surface waters from
  degradation due to development activities.

• The width of the buffer is measured horizontally from
  the normal pool elevation of impounded structures, from
  the bank of each side of streams or rivers, and from the
  mean high water line of tidal waters, perpendicular to
  the shoreline."
 Will I Need A Stormwater Permit?
                          Section A

• Residential                   • Non-Residential
Permitting threshold is one     Permitting threshold is
  acre of land disturbance.       10,000 sq. ft. of land
                                  disturbance
If you are clearing, grading,   Includes projects that
   etc. one acre or more –        disturb less than 10,000
   you will need to apply for     sq. ft. but are part of a
   a state stormwater             larger plan for
   permit.                        development or sale.
SA Waters

• Commercial shellfishing waters.
• Domestic Wastewater Discharges are not
  allowed.
• Provisions for stormwater controls.
• Class SA Waters also carry a supplemental
  designation of HQW (High Quality Water)
  or ORW (Outstanding Resource Water).
    Dare County SA Waters Map

http://h2o.enr.state.nc.us/admin/maps/counties/
              documents/dare.pdf

          Boundaries on map include
       land “within ½ mile of SA waters”
No SA Waters

• Part of Kill Devil Hills, Kitty Hawk,
  Southern Shores, Duck, Currituck Outer
  Banks
• Majority of downtown Manteo
• East Lake
• Bertie, Camden, Chowan, Currituck, Gates,
  Hertford, Perquimans, Tyrell, Washington
   Residential Exclusion

If your lot is part of a larger subdivision that
was issued a stormwater permit, you do not
need to do anything for stormwater runoff –
  you’re already covered under that permit!
I Need a Permit – Next Step:
Determine Built-Upon Area
• As noted previously, wetlands cannot be
  included in the overall project area to calculate
  impervious surface density (BUA).
  – This does not mean that wetlands cannot be
    impacted – the BUA percentage is only used to
    determine whether your project needs to comply
    with LOW DENSITY or HIGH DENSITY stormwater
    requirements.
I Need a Permit:
New Buffer Requirement

• A 50-foot vegetated buffer is required whether
  low or high density; a lawn would qualify as
  “vegetated” – Buffer is similar to “setback”.
  Buffer rules are different in the Tar-Pam and
  Neuse River Basins. (Increased from 30-foot)
Buffer (con’t)
• 30-foot buffer for redevelopment
  – provided there is no net increase in impervious
    surfaces and the redevelopment incorporates equal or
    better stormwater controls that the previous
    development.
  – Provision allows for the rebuilding of homes,
    businesses and other structures in the event of
    natural disasters without mandating strict compliance
    with the new provisions in the rules.
I Need a Permit – Am I Within One-
Half Mile and Draining to SA Waters
• SA Waters Map - DWQ
• Land Quality Map
• Streams or Tributaries on Property
  – If rated as a stream or tributary but not
    appearing on a map – requirements will still
    need to be met and the “within ½ mile” rule
    would include areas adjacent to the stream
    or tributary. (Make sure a ditch is a ditch!)
Yes – I’m Within One-Half Mile …
What is the BUA?
• Low Density – 12% or Less BUA
  – Runoff transported by vegetated conveyances
                    OR
• High Density – Over 12% BUA
  – Control systems must be infiltrations systems,
    wet detention ponds, bioretention systems,
    constructed wetlands, sand filters or
    ALTERNATIVE STORMWATER MANAGEMENT
    SYSTEM.
High Density (con’t)

• Systems will need to control and treat runoff from all
  impervious surfaces by one and one-half inches or
  rainfall or the DIFFERENCE in the runoff from pre and
  post-development conditions for the one-year 24-hour
  storm – whichever is greater. (In Dare County, the one-
  year 24-hour storm condition is approx. 3 ½ inches of
  rain)

• If INFILTRATION meets the requirements under the
  rules then it will be acceptable as an alternative system.
All Permits - Low and High Density
Requirements
• Prohibit new points of stormwater discharge
• No expansion of existing conveyance systems
    draining to SA waters
•   No increase in net amount or rate of discharge
    through existing outfalls
•   Infiltration of the one-year 24-hour storm?
    Intent is “No NEW runoff from the 1-yr 24-hour
    storm. (Confusing and needs clarification)
I Need a Permit but I’m Outside of
One-Half Mile SA …., ETC.
• Low Density – 24% or Less BUA
    – Runoff transported by Vegetated Conveyance
                         OR
•   High Density – Over 24% BUA
    – Control systems must be infiltrations systems, wet
      detention ponds, bioretention systems, constructed
      wetlands, sand filters or ALTERNATIVE
      STORMWATER MANAGEMENT SYSTEM.
    – Must be designed to STORE, control and TREAT
      runoff generated by one and one-half inch or rainfall.
Requirements of Structural Controls

• Same as Phase II
  – Remove an 85% average annual amount of
    Total Suspended Solids
  – For detention ponds – draw down the
    treatment volume no faster than 48 hours,
    but no slower than 120 hours.
  – Discharge volume at a rate = or less than
    pre-development for 1-year, 24-hour storm.
  – Meet General Engineering Design Criteria.
Structural Controls and High-Water
Table Separation
• For controls that require separation from
  seasonal high-water table, a minimum of two
  feet is mandated.

• Need 12 inches of naturally occurring soil above
  the seasonal high water table with a minimum
  soil hydraulic conductivity of 0.52 inches per
  hour.
Summary –
   Permitting Requirements – Sec. A
• If disturbing more than one acre
 residential or 10,000 sq.ft. non-residential
  – Stormwater permit required and
  – 50-ft. vegetated buffer for new development; 30 ft.
    for redevelopment
     • Definition of vegetated buffer different in Neuse and Tar-
       Pam River Basins (can be disturbed; buffer can be a lawn in
       Dare County) and
  – No credit for wetlands in computing built-upon area.
Summary (con’t)
   - Permitting Requirements
• If < ½ mile from and draining to SA waters
  – No new points of discharge; no increase in flow to SA waters.
  – Level spreaders to diffuse any flow through wetland areas
  – 12% or less built-upon area = low density
      • No engineered stormwater controls required on site
      • Stormwater must be primarily conveyed by vegetated conveyances
  – Greater than 12% built-upon area = high density
      • Structural stormwater controls required or any BMP
      • For structural controls, minimum separation of 12” of natural soil
          above seasonal high water table
      •   Need to control and treat the difference in runoff from pre-
          development/post-development one-year 24-hour storm conditions
          within property boundary.
Summary (con’t)
   - Permitting Requirements
• If > ½ mile from and draining to SA
 waters
  – 24% or less built-upon area = low density
     • Stormwater conveyed primarily by vegetated
      conveyances
  – > 24% built-upon area = high density
     • Structural engineered controls required or any BMP
     • Will need to store, control and treat runoff from
      one and one-half inch of rainfall.
  No Stormwater Permit Needed –
         But Part of the Rules!
                    Sections B and C
• New residential development with land disturbance over
  10,000 sq. ft. but less than an acre AND BUA is greater
  than 12% within ½ mile and draining to SA waters
                             OR
 New residential development with land disturbance over
  10,000 sq. ft. AND BUA is greater than 24% outside of
                    ½ mile SA waters.

If lot is part of a larger subdivision that was already issued
       a stormwater permit, then you should not have to
     comply with these rules. (This is not clearly stated in
           Sections B and C and needs to be clarified!)
Within ½ mile….
• Collect all rooftop runoff from one-year 24-hour storm in
  rain barrels or cisterns. All uncovered areas to be paved
  need to be constructed of permeable pavement or other
  pervious material OR
• Direct all rooftop runoff from one-year 24-hour storm to
  a rain garden. All uncovered areas to be paved need to
  be constructed of permeable pavement or other pervious
  material OR
• Install any other BMP to control and treat the difference
  in runoff from pre-development/post development one-
  year/24-hour storm conditions.
Outside of ½ mile, ETC.
• Collect all rooftop runoff from the first 1.5 inches of
  rainfall in rain barrels or cisterns. All uncovered areas to
  be paved need to be constructed of permeable
  pavement or other pervious material OR
• Direct all rooftop runoff from the first 1.5 inches of
  rainfall to a rain garden. All uncovered areas to be paved
  need to be constructed of permeable pavement or other
  pervious material OR
• Install any other BMP to control and treat the runoff the
  first 1.5 inches of rainfall.
CHALLENGES OF RULES
• Intent/Purpose
• DWQ has no statute authority to mandate that local
    governments enforce or monitor sections B and C.
•   Sections B and C will be self-regulating and compliance
    will be complaint-driven.
•   Sections B and C do not specifically exclude lots in
    subdivisions already under a stormwater permit
•   As written, under Section A-2-C combined with A-2-B –
    lots may be unbuildable.
•   Official Maps?
•   Interpretation by local officers?
•   Incorporating local rules
•   Vested Rights?
•   COST $$$$
What’s Next?
• Rules go before Rules Review Commission Feb 21st.
• If sent for Legislative Review
   – Changes and clarifications may be made.
   – If no action taken by Committee, rules as presented become
     effective August 1, 2008.


• Local Cooperation/Control
   – Lot coverage definition – Can we come up with ONE county-wide
     definition?
   – Setback Requirements?
   – County-wide USMP?
    Universal Stormwater Management Plan
                   (USMP)

• Local control of stormwater rules
• Supersedes Coastal Stormwater Rules
• Permitting threshold would be 10,000 Sq. Ft. of land
    disturbance
•   Plan would have to meet minimum requirements
    approved by DWQ
•   Permit issued locally – municipality or County
•   Rule language:
    http://h2o.enr.state.nc.us/su/documents/MicrosoftWord-
    USMP-FinalEffectiveRule_.pdf
•   More info: http://h2o.enr.state.nc.us/su/usmp.htm
                Additional info:

    Division of Water Quality – Tom Reeder
Environmental Supervisor - 919-733-5083 x 528
             tom.reeder@ncmail.net
               FAX: 919-733-9612


         Website on Stormwater Rules:
   http://h2o.enr.state.nc.us/su/coastal.htm
          Questions?
Willo Kelly – Government Affairs Director
Outer Banks Home Builders Association
    Outer Banks Realtors Association
           willokelly@gmail.com