comprehensive floodplain management promoting wise uses of floodplains l.
Skip this Video
Loading SlideShow in 5 Seconds..
COMPREHENSIVE FLOODPLAIN MANAGEMENT : Promoting Wise Uses of Floodplains PowerPoint Presentation
Download Presentation

Loading in 2 Seconds...

play fullscreen
1 / 63

COMPREHENSIVE FLOODPLAIN MANAGEMENT : Promoting Wise Uses of Floodplains - PowerPoint PPT Presentation

  • Uploaded on

CA Department of Water Resources/ CIFMCG Workshop. COMPREHENSIVE FLOODPLAIN MANAGEMENT : Promoting Wise Uses of Floodplains. July 2006. Comprehensive Floodplain Management Workshop. No Adverse Impact Strategies. Workshop Modules. Comprehensive FPM NFIP Overview

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'COMPREHENSIVE FLOODPLAIN MANAGEMENT : Promoting Wise Uses of Floodplains' - yin

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
workshop modules
Workshop Modules
  • Comprehensive FPM
  • NFIP Overview
  • FPM No Adverse Impact Strategies
  • Natural Floodplain Functions and Societal Values
  • Flood Management Economic AnalysisEcosystem Evaluation Methods
  • Case Study
  • Technical and Financial Assistance
no adverse impact
No Adverse Impact
  • Background
  • Strategies
  • Overcoming Legal Barriers
no adverse impact5
No Adverse Impact
  • Background
  • NAI Strategies
  • Overcoming Legal Barriers
nai background
NAI Background
  • NAI is being proposed by the ASFPM to:
    • Ensure the actions of any community or property owner do not adversely impact others
    • Incorporate multi-objective and watershed planning principles
  • NAI doesn’t mean “no development”
  • NAI means that any adverse impact caused by a project must be mitigated, preferably based on a community or watershed-based plan
nai background7
NAI Background
  • Types of adverse impacts:
    • Increased flood stages, velocities, flows
    • Increased potential for erosion and sedimentation
    • Increased cost of public services
    • Degradation of water quality
  • Impacts may occur anywhere in the watershed
nai background8
NAI Background
  • Benefits of NAI:
    • Reduce flood losses over time in your community
    • Reduce likelihood of your actions increasing flood damage to others
    • Reduce challenges and lawsuits
    • Receive recognition through the Community Rating System
    • Incorporate multiple objectives
    • Protect natural resources and values of floodplains
no adverse impact9
No Adverse Impact
  • Background
  • NAI Strategies
  • Overcoming Legal Barriers
nai strategies
NAI Strategies
  • Hazard identification
  • Education and outreach
  • Planning
  • Regulations and development standards
  • Mitigation
  • Infrastructure
  • Emergency services
nai strategies11
Strategies grouped according to:




Source: ASFPM, No Adverse Impact: A Toolkit for Common Sense Floodplain Management (2003)

NAI Strategies

nai strategies12
NAI Strategies
  • Hazard identification
  • Education and outreach
  • Planning
  • Regulations and development standards
  • Mitigation
  • Infrastructure
  • Emergency services
hazard identification basic strategies
Hazard Identification Basic Strategies
  • Join NFIP
    • FIS Study
    • Flood Insurance Rate Map
    • Adopt FPM ordinance
  • Maintain FIRM and enforce FPM ordinance
hazard identification better strategies
Hazard IdentificationBetter Strategies
  • Strengthen Approximate A Zone requirements
    • NFIP only requires detailed data if development is larger than 5 acres or 50 lots
    • Require developers provide detailed flood data for all developments
  • Develop better base map for FIRM
    • Smaller contour intervals
    • Include more recent land use information
  • Include local coastal program boundaries on FIRM

hazard identification better strategies15
Hazard IdentificationBetter Strategies
  • Map other flood related hazards
    • Uncertain flow paths
    • Closed/restricted outflow basin lakes
    • Debris and sediment blockage
    • Land subsidence
    • Mudflows
    • Dam failure inundation
    • Tsunamis
    • Coastal and riverine erosion
hazard identification nai strategies
Hazard IdentificationNAI Strategies
  • Use future conditions hydrology to develop maps
    • Flood discharges based upon projected land use changes
    • Future condition floodplains can be shown on FIRMs for “informational” purposes
hazard identification nai strategies17
Hazard IdentificationNAI Strategies
  • Adopt higher floodway mapping standards
  • Assume entire floodplain is a floodway
    • Floodway standards are in effect across entire floodplain
    • Development cannot cause any increase in BFE which might affect others
hazard identification nai strategies18
Hazard IdentificationNAI Strategies
  • Require no loss of storage or velocity increases
    • Communities can require that floodway delineation be based on preventing a loss of storage and/or increase in velocity
    • Example: Illinois requires floodways to be mapped using a 0.1 ft allowable rise, and a maximum 10% increase in velocity with a maximum 10% loss of floodplain storage
nai strategies19
NAI Strategies
  • Hazard identification
  • Education and outreach
  • Planning
  • Regulations and development standards
  • Mitigation
  • Infrastructure
  • Emergency services
education outreach basic strategies
Education & OutreachBasic Strategies
  • Make documents and maps available to the public
    • FISs/FIRMs
    • Permit records
  • Have staff available to answer questions
    • Is my property in the floodplain?
    • What is the base flood elevation?
    • What development regulations apply to me?
    • Where do I go for flood insurance?
education outreach better strategies
Education & OutreachBetter Strategies
  • Implement risk communication program
    • Advise residents and businesses of flood hazards
    • Provide information as to what is being done
    • Provide information on how residents can protect themselves
    • Use different tactics (ex: websites, utility bill leaflets, etc.)
education outreach sacramento hypothetical flood maps
Education & OutreachSacramento Hypothetical Flood Maps

education outreach sacramento evacuation maps
Education & OutreachSacramento Evacuation Maps

education outreach better strategies24
Education & OutreachBetter Strategies
  • Show additional information
    • Aerial photos of buildings superimposed on FIRMs
    • Show additional hazards (alluvial fans, mudflows)
    • Show possible flooding outside of mapped areas
education outreach better strategies25
Education & OutreachBetter Strategies
  • Implement outreach programs
    • Brochures/displays in public places
    • Newspaper articles
    • Utility bill inserts
    • Flood protection videos
    • Neighborhood presentations
    • Floodplain signs
    • Websites

(ex: )

education outreach nai strategies
Education & OutreachNAI Strategies
  • Educate staff, decision makers and the public
    • FEMA/State/ASFPM NFIP workshops and courses
    • Certified Floodplain Manager Program
    • Distribute NAI brochures, posters and videos
    • Develop models or presentations
    • Develop school environmental and safety education programs
nai strategies27
NAI Strategies
  • Hazard identification
  • Education and outreach
  • Planning
  • Regulations and development standards
  • Mitigation
  • Infrastructure
  • Emergency services
planning basic strategies
PlanningBasic Strategies
  • Prepare comprehensive land use plans
    • Identify hazard areas
    • Identify appropriate land uses
  • Develop special subject plans to supplement comprehensive plans
    • Economic development plan
    • Habitat protection plan
    • Watershed management plan
  • Adopt zoning or other ordinances to enforce plans
planning better strategies
PlanningBetter Strategies
  • Identify flood-risk areas on plans and restrict development
  • Adopt low-density zoning in floodplains
  • Use specialized tools (ex: GIS, HAZUS, HEC-FDA, etc.)
  • Prepare FPM, storm water management and special area plans to supplement comprehensive plans
  • Prepare multi-hazard mitigation plans
planning better strategies30
Planning Better Strategies
  • Floodplain Management Plans
    • Identify flood prone/repetitive loss areas
    • Evaluate various flood damage reduction measures
    • Recommend actions for the community
    • Identify mapping needs
  • Multi-Hazard Management Plans
    • Identify all natural hazard areas
    • Evaluate various hazard mitigation measures
    • Recommend actions for the community
planning nai strategies
PlanningNAI Strategies
  • Include watershed, MOM and sustainable development principles in land use planning
    • Consider current and future development
    • Coordinate floodplain planning with other planning activities (economic development, housing, recreation, ecosystem restoration, water quality, etc.)
    • Identify long-term implications of alternative land uses
    • Promote “sustainable” development
planning nai strategies32
PlanningNAI Strategies

Sustainable development is “…meeting the needs of the present without compromising the ability of future generations to meet their own needs.”

(ASFPM, NAI Toolkit)

planning nai strategies33
PlanningNAI Strategies
  • Governor’s Office of Planning and Research has incorporated floodplain management into its General Plan Guidelines as an “optional” element

nai strategies34
NAI Strategies
  • Hazard identification
  • Education and outreach
  • Planning
  • Regulations and development standards
  • Mitigation
  • Infrastructure
  • Emergency services
regulation development standards basic strategies
Regulation & Development StandardsBasic Strategies
  • Adopt separate FPM ordinance with minimum FPM regulations
  • NFIP estimates that buildings built to minimum standards suffer 70% less than unprotected buildings
  • Flood damage can still occur with minimum standards
  • BFEs subject to change, particularly as development occurs in watershed
regulation development standards basic strategies36
Regulation & Development StandardsBasic Strategies
  • Example minimum FPM regulations
    • All development in 100-yr floodplain must have a permit
    • Development in floodway must not cause increase in base flood levels
    • New residential buildings in riverine floodplains must have top of lowest floor elevated above BFE
    • New non-residential buildings in riverine floodplains must have top of lowest floor elevated to the BFE or flood proofed 1 foot above BFE
    • Substantially improved buildings (costs exceeding 50% of market value) are considered “new” buildings
regulation development standards better strategies
Regulation & Development StandardsBetter Strategies
  • Adopt NFIP regulations with higher standards
  • Receive Community Rating System Credit for higher standards and lower insurance premiums for your community
  • CA Model Ordinance:

regulation development standards better strategies38
Regulation & Development StandardsBetter Strategies
  • Require additional height requirement above BFE (“freeboard”)
    • Accounts for rise in BFE due to development in floodplain and the watershed
    • Accounts for uncertainties inherent in flood modeling
    • Results in significantly lower flood insurance rates (almost a 50% reduction in building and contents rates by adding one foot of freeboard)
    • Most common higher regulatory standard adopted by states and communities
regulation development standards better strategies39
Regulation & Development StandardsBetter Strategies
  • Strengthen “substantially improved” building requirements
    • For each structure, count substantial improvements cumulatively rather than individually to reach 50% threshold
    • Lower 50% threshold value
    • All additions outside original building footprint must meet building protection standards
regulation development standards better strategies40
Regulation & Development StandardsBetter Strategies
  • Flood fringe development
    • Require buildings to be built on columns, not fill
    • If buildings built on fill, require compensatory storage (ex: storage equal to1.5 or 2 times amount of fill)
  • Adopt International Building Codes which include flood reduction standards
  • Adopt subdivision standards that require structures to be built outside of hazard areas
regulation development standards better strategies41
Regulation & Development StandardsBetter Strategies
  • Utilize “green infrastructure”
    • Green space includes large metro and neighborhood parks, riparian buffers, linear parks and greenbelts
    • Green space is used as infrastructure just like roads, water lines and sewers
    • Green space provides services that are useful to humans, such as storm water storage and conveyance
    • Include green space to avoid more costly structural solutions

regulation development standards better strategies42
Regulation & Development StandardsBetter Strategies
  • Adopt storm water regulations
    • Require developers to include detention basins
    • Require less impervious materials
    • Slow surface runoff using terraces, contour strip farming, sediment fences, hay or straw bales, etc.
    • Develop erosion and sediment control models
  • Adopt higher health and safety standards
    • Keep septic systems and landfills out of floodplains
    • Restrict hazardous materials in floodplains (exs: gasoline, pesticides and chemicals)
regulation development standards nai strategies
Regulation & Development StandardsNAI Strategies
  • Preserve beneficial natural floodplain functions
    • Adopt setback standards to establish minimum distances from river channels or shorelines
    • Adopt buffer zone requirements between sensitive and developed areas
    • Adopt proactive developer requirements
    • Implement stream restoration programs
nai strategies44
NAI Strategies
  • Hazard identification
  • Education and outreach
  • Planning
  • Regulations and development standards
  • Mitigation
  • Infrastructure
  • Emergency services
mitigation basic strategies
Mitigation Basic Strategies
  • Implement structural flood management measures
    • Reservoirs
    • Levees
    • Channel modifications
    • Dredging
    • By-passes
  • Make flood insurance available
mitigation better strategies
Mitigation Better Strategies
  • Implement non-structural flood management measures
    • Enforcement of community rules, regulations and procedures
    • Dry and wet flood proofing
    • Building elevation
    • Building relocation
    • Building acquisition/demolition
mitigation nai strategies
Mitigation NAI Strategies
  • Implement master flood planning (ex: integrate watershed, storm water, habitat protection and FPM planning efforts)
  • Involve all stakeholders in planning process
  • Mitigate while not transferring flood problems elsewhere
nai strategies48
NAI Strategies
  • Hazard identification
  • Education and outreach
  • Planning
  • Regulations and development standards
  • Mitigation
  • Infrastructure
  • Emergency services
infrastructure basic strategies
InfrastructureBasic Strategies
  • Minimal flood planning
  • Respond to events as they happen
  • Repair or replace damaged facilities with similar facilities
infrastructure better strategies
InfrastructureBetter Strategies
  • Inventory flood-prone facilities
  • Take actions to protect flood-prone facilities
  • Set protection standards for new facilities
  • Obtain flood insurance
  • Develop emergency action plans
infrastructure nai strategies
InfrastructureNAI Strategies
  • Coordinate capital improvement plans with FPM plans
  • Set higher regulatory standards for critical facilities (ex: protect facilities from 500-yr event)
  • Use “green infrastructure” to reduce maintenance costs and achieve other benefits
nai strategies52
NAI Strategies
  • Hazard identification
  • Education and outreach
  • Planning
  • Regulations and development standards
  • Mitigation
  • Infrastructure
  • Emergency services
emergency services basic strategies
Emergency ServicesBasic Strategies
  • Prepare generic emergency response plan based upon off-the-shelf “model” plans
  • Plans may not meet needs of specific communities
emergency services better strategies
Emergency ServicesBetter Strategies
  • Prepare flood preparedness plans
  • Prepare flood stage forecast maps
  • Prepare dam/levee failure emergency action plans
  • Implement flood warning systems
  • Identify flood response actions and responsible parties
emergency services nai strategies
Emergency ServicesNAI Strategies
  • Improve pre- and post disaster preparedness and procedures (ex: improve methods to evaluate damaged buildings)
  • Apply for pre- and post disaster mitigation funds
  • Incorporate MOM/sustainability principles into post-disaster plans and actions
no adverse impact56
No Adverse Impact
  • Background
  • NAI Strategies
  • Overcoming Legal Barriers
overcoming legal barriers
Overcoming Legal Barriers
  • ASFPM is researching common FPM case law questions:
overcoming legal barriers58
Overcoming Legal Barriers
  • When are public agencies most likely to be held liable for increasing flood or erosion damage on private lands? By…
    • Blocking natural drainage because of grading, fill, or structures (bridges, culverts, etc.)
    • Increasing the location and amount of runoff because of channelization or other drainage projects
    • Constructing flood control works such as levees and dams
    • Inadequately maintaining flood control and related structures
    • Performing inadequate inspections
    • Approving development that increases flood damage on other lands
overcoming legal barriers59
Overcoming Legal Barriers
  • Have courts upheld the overall constitutionality of state and local floodplain regulations?
    • Yes; courts at all levels have broadly and repeatedly upheld the validity of FPM regulations in the last 15 years
  • What have been the most common challenges to FPM regulations in the last 15 years?
    • Regulators permitted construction that later caused damage
    • Unconstitutional over-regulation, or “taking”, of property without payment of just compensation
overcoming legal barriers60
Overcoming Legal Barriers
  • May a local government adopt floodplain regulations that exceed State or Federal (NFIP) minimum standards?
    • Yes; local government regulations may exceed state or federal regulations
    • NFIP regulations specifically encourage state and local regulations that exceed minimum federal standards
overcoming legal barriers61
Overcoming Legal Barriers
  • How can a local government avoid successful legal challenges?
    • Regulations must be based on principles of hazard prevention and “no adverse impact” to others
    • Regulations must be applied fairly and uniformly Include exemption and variance provisions
    • Allow some economic uses of the regulated land
    • For floodplain areas, adopt large-lot zoning which permits some economic use on the upland portion of each lot
    • Allow for the transfer of development rights from floodplain to non-floodplain parcels
    • Fairly tax and levy assessments on economic uses which will be allowed
to summarize
To Summarize…
  • ASFPM No Adverse Impact strategies:
    • Hazard identification
    • Education and outreach
    • Regulations and development standards
    • Planning
    • Mitigation
    • Infrastructure
    • Emergency services
  • Strategies grouped by:
    • Basic
    • Better
    • No Adverse Impact
  • Communities are encouraged to go beyond basic strategies

what s next
What’s Next?
  • Natural floodplain functions and societal values