Future of the Big Darby Watershed

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Future of the Big Darby Watershed

• Steven Gordon
• December, 2001

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Where are we going?

• Current status of stream health
• How development trends will impact it
• Preserving the quality
• What do we need to do?
• How can we get there?

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The Good News

• The Big Darby is still a very high quality stream
• Data show continued good health in most areas
• We have an opportunity to keep it that way

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Impacts of Trends

• Noticed that there are several problem areas
  where deterioration of quality has occurred
• What is this related to?
• How might it change in the future?

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Model of IBI in ECBP

• Eastern Cornbelt Plains Ecoregion

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Major Differences Among Watersheds

• Differences in habitat quality
• Measured by components of QHEI (Qualitative
  Habitat Evaluation Index)
• Reflect changes in riparian zone quality
• Differences in point source pollution
• Differences in land use/non-point source
  pollution
• Urban land use a key

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Web-Based Tools

• Http//tycho.cfm.ohio-state.edu
• How does this fit with current trends?
• Analysis done by my students last Spring
• Study sponsored by the Darby Creek Association
• Urban growth in the basin is substantial
• A reasonable forecast shows major additional
  growth

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Growth Rate Assumptions

• Growth rate (not absolute number of persons) was
  held constant with the following assumptions
• Extremely high growth rate areas would fill up
  with people and growth will decline
• Areas adjacent to high growth regions will have
  an increased rate of growth
• No growth controls are in place in order to
  restrict development anywhere in the watershed

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Rates of Population Change

• Population Change
• Forecasting model based on population rates of
  change from 1990 to 2000
• Rates of change varied from -31 to 211, but
  most between -2 and 40

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Growth Rate Assumptions

• Rates of change that were significantly high (80
  to 211) were halved because of high growth and
  only moderate projected county growth by the ODOD
• Tracts within Counties with high anticipated
  growth were increased (12.5 to 25 based on ODOD
  data) depending on adjacency to historically high
  growth tracts

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Results
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Results Continued
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Comparison with Model

• Model forecast about a 25 growth with lower base
• Population forecast pushes rates to 50 for some
  tracts
• Will accelerate deterioration in growth areas
• Probably have a time-scale of 10-15 years unless
  something changes

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What needs to be done?

• Action by all communities
• From cities to townships to counties
• From farmers to residents to developers
• A combination of approaches
• Protect and improve the riparian zone
• Best management practices for all uses for all
  areas
• Reduction in total growth

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Consequences of Inaction

• Continuing decline of stream quality
• Loss of communities
• Increased flooding
• Loss of prime farmland
• Loss of agricultural communities/mix
• Loss of open space
• Increases in congestion and other urban problems

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Possible Actions

• Riparian zone protection
• BMP controls in zoning and subdivision
• Strict enforcement
• Conservation easements or other land banking
  techniques

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How do we get there?