Integrating BMP Planning with Ordinance Development

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Integrating BMP Planning with Ordinance
Development

• David H. Hunter
• City of Denton

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Dentons Location in Denton County
North
Denton City Limits
Lake Ray Roberts
Sanger
Krum
Ponder
Pilot Point
Denton
I-35W
Waste water
Corinth
Intake
I-35E
Lake Grapevine
Lake Lewisville
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Development pressuresExample of Land Cover
Changes
March 2001
March 2004
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Denton Watershed Approach to Storm Water
Management

• Environmentally Sensitive Area Management
• Open Space Preservation
• Oil and Gas Regulation
• Tree Preservation Code

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Effects of the Denton Development Code

• Decision Making System
• Site Design Standards
• Environmentally Sensitive Areas
• Land Division Regulations
• Zoning Districts
• Zoning Map

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Ecosystem Habitat

• Protecting and restoring these habitats requires
  an understanding of comprehensive ecosystem
  function and all the interconnections that
  combine to support the health of any particular
  habitat.

Ecosystem Habitat
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Structure of ESA ordinance ESA classes

• Developed floodplain FEMA 100-year floodplain,
  but developed
• Undeveloped floodplain same, but undeveloped
• Riparian buffers areas immediately adjacent to
  a surface water conveyance. 50ft to 100ft,
  depending on drainage basin size. No drainage
  area size cutoff
• Water Related Habitats Wetlands or areas
  containing significant hydrophytic vegetation
• Upland habitat remnants of the Eastern
  Crosstimbers forests, 10 acres in size or larger.

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Protective measures

• Developed floodplains basically, only FEMA fill
  requirements and local drainage code applies
• Undeveloped floodplain, riparian buffers and
  water related resources
• No handling processing or storing hazardous
  wastes
• No land disturbing activities unless authorized
  by a USACE 404 permit or letter of permission AND
  the director of planning
• No structures
• NO tree or understory vegetation removal

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City of Denton
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City of Denton with streams
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Riparian Buffer 50 ft.
Riparian Buffer 100 ft.
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Undeveloped Floodplain
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Upland Habitat
Water Related Habitat
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SuburbanWatershedProtection Begins At320
Acres288,884 ft. Stream Buffered
slide provided by Mike Lyday, City of Austin
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Suburban Watershed64 AcreDrainage area
Protected553,381 ft.StreamBuffered
slide provided by Mike Lyday, City of Austin
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Suburban Watershed5 Acre Protection1,638,372
ft.HeadwaterProtection
slide provided by Mike Lyday, City of Austin
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Aerial Photograph
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Rivers, Streams and Open Water
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Riparian Areas
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Water-related Habitat
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Floodplain
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Upland Habitat
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Study Area
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Primary Road
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Connecting Roads
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Development Concept
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Conceptual vs Real World

• What about situations where large developments
  will essentially change the entire landscape are
  an area and ESA are limited.
• Political and economic influences are constant
  game-changers.

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Rayzor Ranch

• City of Denton experience with Master Planned
  Communities
• 410 acre mixed-use development featuring
  residential, retail, hotel, office, medical
  facilities, public parks, museums, entertainment
  and state of the art outdoor amphitheater

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Rayzor Ranch contd
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Rayzor Ranch

• Rayzor Ranch is a planned 850 million dollar
  mixed-use development on 400 acres of prime North
  Texas real estate. The site is the former Rayzor
  family Hillview Ranch which features a hill with
  a commanding view of what will become the
  largest, super-regional development between
  Dallas and Oklahoma City.

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BMPs for Master Planned Communities

• Rayzors site drainage analysis identified hot
  spot land uses (parking lot areas, service
  stations, trash receptacle areas, loading zones,
  etc.) with high pollution generating potential.

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Integrated Storm Water Management

• City Staff saw opportunity in the fact that
  Rayzor Ranch was impacting riparian buffers,
  floodplain and a downstream recreational lake.
• The City chose to request an integrated storm
  water/water quality approach from the developer.

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History of ISWM

• The iSWM Design Manual for Site Development and
  Design Manual for Construction are cooperative
  initiatives that assist cities and counties to
  achieve their goals of water quality protection,
  streambank protection, and flood control. They
  also help communities meet their construction and
  post-construction obligations under state storm
  water permits.
• http//www.nctcog.org/envir/SEEDevEx/iswm/index.as
  p

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Principles of iSWM

• 1. The site design should utilize an integrated
  approach to deal with storm water quality
  protection, streambank protection, and flood
  control requirements.
• 2. Storm water management practices should strive
  to utilize the natural drainage system and
  require as little maintenance as possible.

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Principles of iSWM

• 3. Structural storm water controls should be
  implemented only after all site design and
  nonstructural options have been exhausted.
• 4. Structural storm water solutions should
  attempt to be multi-purpose and be aesthetically
  integrated into a sites design.
• 5. One size does not fit all in terms of storm
  water management solutions.

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Rayzor Ranch

• Rayzor selected a combination of structural and
  non-structural water controls to assembly a
  treatment train capable of meeting the
  established water quality removal thresholds.
• Among the controls selected, the use of enhanced
  swales, filter strips, bio-retention areas,
  pocket wetlands, and a water quality pond have
  been strategically located throughout the
  northern tract.

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Rayzor Ranch Development
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Reduction Rates
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Conclusions for ESAs in Denton

• ESAs were considered important to protect
• The current process is ecologically based, and is
  supported by local ordinances
• Overall, this approach has produced a practical
  tool for landuse regulation and a useful Best
  Management Practice.
• There are areas for improvement

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www.cityofdenton.com/watershed
General Comments and Questions
Are there any issues we overlooked?