FUNDING FOR DEVELOPMENT OF STATEWIDE LAND COVER

DATA

Jennifer Tribo, Senior Water Resources Planner Hampton Roads Planning District Commission

VGIN Advisory Board MeetingJanuary 6, 2014

ProposalDevelop a high resolution land cover layer in order to improve pollutant loading estimates for Virginia in Phase 6 of the Chesapeake Bay Models.

Why Now?

Chesapeake Bay TMDL/Implement

ation Plan

Phase II Watershed

Implementation Plans

Midpoint Assessment

TMDL Goals Met

2010 2012 2017 2025

Land Cover and the Chesapeake Bay TMDL

Land cover data is utilized by the Bay Models to calculate loads and load reductions for local governments.

Chesapeake Bay Background

Current land cover data derived from 30-meter Landsat imagery. Underestimates impervious cover in rural areas Underestimates vegetation in dense urban areas Overestimates agricultural areas

Discrepancies between Baywide data and local scale data caused accountability and implementation issues during development of TMDL and Implementation Plans.

Bay Program utilized ancillary data to improve data quality, and pledged to further improve data for 2017 model revisions.

Data ComparisonHigh Resolution Data 30 Meter Landsat Data

Dense Urban Area

Suburban area

Chesapeake Bay Background Cont. Localities advocated for use of local data in

2017. Land Use Workgroup was established by Bay

Program in 2012 to establish protocols. Data survey of Bay Watershed local governments

showed wide variations in data quality and availability.

Data for Virginia was only available in highly urbanized counties and quality varied widely.

Local scale land cover data due to the Bay Program by Summer 2015.

Uses for High Resolution Land Cover Data

Quantify changes in development over time.

Identify natural resources at risk from development.

Quantify impervious surfaces in urban areas. Utilize for stormwater utility development. Estimate stormwater pollutant loads and

reductions. Track urban tree canopy coverage. Evaluate effectiveness of land

conservation or restoration initiatives.

Potential State Agency Partners

Benefits of Statewide Land Cover Data

Consistent methodologies, classification systems, and scale.

Cost savings for bulk analysis and single contract.

Data available to localities and all state agencies.

Proposed Methodology Utilize 4 band orthophotography to develop

5-7 classes of land cover data. 2011 for western localities 2013 for eastern localities

Proposed Methodology Cont. Resolution may vary from 1

foot to 5 meters depending on location.

Proposed classes Impervious surface

(separate buildings, roads, and sidewalks/parking lots in urban areas).

Woody land cover Non woody land cover Emergent wetlands Agriculture Water Barren

Who Would Conduct Analysis?

The Sanborn Map Company, Inc. Holds existing contract for providing

orthoimagery to VITA through 2016. Most efficient option in terms of time.

Other entity VITA would have to put services out for bid. Could be more cost effective.

Estimated Costs Utilizing current Sanborn land cover

specifications: Baywide – approximately $4 million Statewide – approximately $6 million

HRPDC and VGIN staff working with Sanborn to refine cost estimate and data specifications.

Next Steps Propose budget amendment through

general assembly. Earmark Water Quality Improvement Fund

(WQIF) or Stormwater Local Assistance Fund.

Pull from partner agency budgets.

DEQ funds through WQIF and recoups some costs through agreements with partner agencies.