Assessing Implementation of Management Practices and Their Relation to Water Quality. Presentation by Dianna Hogan, Taylor Jarnagin, Keith VanNess, Jennifer St.John, and Rachel Gauza, March 25, 2009
Suburban Land Use, Stormwater Best Management Practices, and Receiving Stream Health
1. Suburban Land Use,
Stormwater Best Management Practices,
and Receiving Stream Health
Assessing Implementation of Management Practices
and Their Relation to Water Quality
Dianna Hogan1, Taylor Jarnagin2, Keith VanNess3, Jennifer St.John3, and Rachel Gauza3
1USGSEastern Geographic Science Center
2EPA Landscape Ecology Branch, Environmental Sciences Division
3Montgomery County Department of Environmental Protection
March 25, 2009
2. Clarksburg Special Protection Area (CSPA)
Presentation Overview
Definition (BMP)
Partnership and goals
Study site description
Detention pond and
sand filter
Selected methods and preliminary findings
Local level BMP database that maps development, BMP type
and placement, and landscape stormwater flow direction
Four Light Detection And Ranging (LiDAR) overflights
Monitoring of physical and biological parameters
3. Which Best Management Practices (BMPs)?
Suburban land management actions
above/below ground retention or infiltration, wet or dry ponds,
sand/gravel filters, constructed wetlands, vegetated buffer strips,
etc.
Designed to lessen impacts of suburban land use by treating
and/or retaining or detaining stormwater runoff
filtration
Splitter with vent
recharge trench
detention basin
4. Clarksburg Special Protection Area (CSPA)
Partnership
Montgomery County Department of Environmental Protection (DEP)
Montgomery County Department of Permitting Services (DPS)
Maryland-National Capital Park and Planning Commission
University of Maryland College Park (UMDCP)
Virginia Polytechnic Institute and State University
USEPA Landscape Ecology Branch, Ecosystems Research
Division, and Office of Water
US Geological Survey (USGS) Eastern Geographic Science Center
(EGSC) and Water Resources Discipline (WRD)
5. Clarksburg Special Protection Area (CSPA)
Partnership Goals
Study the impacts of land use change
Agriculture / forest to suburban
Document how the changes in topography and imperviousness
affect the hydrology, biology, chemistry, and geomorphology of
receiving streams
Assess the effectiveness of local level BMP mitigation protocols
Goal: Better understand the potential pollutant retention of
specific BMP mitigation designs and promote the application of
this information across the Chesapeake Bay region
6. Clarksburg Special Protection Area (CSPA)
Study Site Description
Developing under SPA guidelines
Designed to protect high quality
streams in developing areas
Advanced sediment and erosion
controls, stormwater BMPs in series,
interception of water further upstream
Before-after control study
5 subwatersheds (0.9 – 3.4 km2)
Undeveloped positive control on
parkland
Developed negative control in
Germantown (completely built out;
pre-2000 criteria)
Three test areas
5 USGS stream gages (red dots)
Water quality (blue dots)
2 precipitation gages (near Sopers
and Cabin Branch)
7. Clarksburg Special Protection Area (CSPA)
Methods and Preliminary Findings: BMP Database
Local level BMP database (GIS)
Pre- and post-development
Building footprints, roads
Stormwater management infrastructure and conveyance (pipes, swales,
treatment trains)
BMP type, placement, DA, IC
Stormwater flow direction
Integrate land use and BMP information with chemical, biologic,
and physical stream data
Study local level BMP protocols for water quality mitigation
Effect of BMP type, location, use in series or as individuals, and
development patterns
8. Clarksburg Special Protection Area (CSPA)
Methods and Preliminary Findings: BMP Database
Inclusive
retention or infiltration areas, wet ponds, extended
detention ponds, sand filters, etc.
private BMPs - dry wells along the back side of houses by
streams
Temporal
Sediment and erosion control during construction (settling
for large volumes of sediment-laden runoff)
Stormwater management post-construction (quantity and
quality control of stormwater runoff)
Dry well
Clarksburg, MD 9/05
Dry well schematic
Adjacent sediment trap prior
Sand filter
to conversion to a detention
Clarksburg, MD 5/06
basin Clarksburg, MD 5/06
10. Clarksburg Special Protection Area (CSPA)
Methods and Preliminary Findings: LiDAR
Four Light Detection And Ranging
(LiDAR) overflights
2002, 2004, 2007, 2008
Optical remote sensing
Measures properties of scattered
light to determine distance by
measuring time delay between
transmission and detection of the After, Flood, 1997
reflected signal
Map temporal changes in the
landscape, stream morphology,
watershed hydrology, infiltration
conditions, and used for
hydrological modeling Z
Y
X
11. Clarksburg Maryland Special Protection Area: Tributary 104 site
2002 USGS Stream Gauge Site
Jarnagin 2008 EPA LEB
12. Clarksburg Maryland Special Protection Area: Tributary 104 site
2002 USGS Stream Gauge Site
Jarnagin 2008 EPA LEB
13. Clarksburg Maryland Special Protection Area: Tributary 104 site
2004 USGS Stream Gauge Site
Jarnagin 2008 EPA LEB
14. Clarksburg Maryland Special Protection Area: Tributary 104 site
2004 USGS Stream Gauge Site
Jarnagin 2008 EPA LEB
15. Clarksburg Maryland Special Protection Area: Tributary 104 site
2006 USGS Stream Gauge Site
Jarnagin 2008 EPA LEB
16. Clarksburg Maryland Special Protection Area: Tributary 104 site
2005 post constr. BMP
2006 USGS Stream Gauge Site
Jarnagin 2008 EPA LEB
17. Clarksburg Maryland Special Protection Area: Tributary 104 site
2007 USGS Stream Gauge Site
Jarnagin 2008 EPA LEB
18. Clarksburg Maryland Special Protection Area: Tributary 104 site
2008 USGS Stream Gauge Site
Jarnagin 2009 EPA LEB
19. Clarksburg Maryland Special Protection Area: Tributary 104 site
2008 USGS Stream Gauge Site
Jarnagin 2009 EPA LEB
20. Clarksburg Special Protection Area (CSPA)
Methods and Preliminary Findings: Monitoring
Monitoring of physical and biological parameters
Stream flow (USGS flow gages at each subwatershed)
Stream monitoring focusing on rapid habitat assessment, geomorphology,
water temperature, sediment, and benthic macroinvertebrates
Precipitation gages (2)
Selected BMP monitoring
Integration of monitoring data with the BMP database
Preliminary findings in developing areas:
Stream conditions have declined
Flashier storm response
Altered stream geomorphology (bed
aggradation during development then
channel erosion postdevelopment)
Sinuosity ratio indicates channel
straightening
21. Clarksburg Special Protection Area (CSPA)
Methods and Preliminary Findings: Monitoring
Average Stream Conditions
(combined benthic macroinvertebrate and fish scores)
22. Clarksburg Special Protection Area (CSPA)
Summary
Few studies have followed comparable small watersheds from pre-construction
through build-out to evaluate various combinations of stormwater management
mitigation
Development in the CSPA is ongoing - need to be further in the development
process for trend analysis and determine if there will be recovery
Increasing targeted monitoring efforts – USGS postdoc and discussing sediment
collection
We will continue to evaluate the effectiveness of different BMPs and water quality
protection measures
Correlate changes in stream flow,
biological and chemical
parameters, and geomorphology
with development patterns and the
BMPs used to mitigate the impacts
of development
1998 2008
23. THANK YOU !
Dianna Hogan
dhogan@usgs.gov
Taylor Jarnagin
Jarnagin.Taylor@epamail.epa.gov
Keith VanNess
Keith.VanNess@montgomerycountymd.gov
Jennifer St.John
Jennifer.St.John@montgomerycountymd.gov
Rachel Gauza
Rachel.Gauza@montgomerycountymd.gov
Hogan, D., Jarnagin, T., VanNess, K., St.John, J., Gauza, R., 2009, Suburban Land
Use, Stormwater Best Management Practices, and Receiving Stream Health [abs.]:
Ecosystem Based Management - The Chesapeake and Other Systems, p. D-45.