Roadside Ditches, Stormwater Management, and Stream … · Roadside Ditches, Stormwater Management,...
-
Upload
nguyendung -
Category
Documents
-
view
232 -
download
3
Transcript of Roadside Ditches, Stormwater Management, and Stream … · Roadside Ditches, Stormwater Management,...
Roadside Ditches, Stormwater Management,
and Stream Health in New York
Rebecca SchneiderRoadside Ditch ProgramDept. Natural Resources,
Cornell University Juan Diaz-Robles (CEE), Art Lembo (CSS)Nancy Trautmann, (DNR), Todd Walter (BEE)Sharon Anderson (Cayuga Lake Watershed Network)
Quantity and quality of water in our lakes and streams,
arelinked to
adjacent landuses and human
activities.
ImperviousSurfaces:RooftopsParking lotsDriveways
Compacted Soils:Lawns,Crop fields
E.P.A. Phase II Stormwater Regulations 2003For 450 towns in New York – Municipal Separate Storm Sewer Systems
Rt. 89, Tompkins Co., Feb 2006
Main focus is on construction activities
Roadside Ditches:the unrecognized factor
in stormwaterrunoff management
Managed by highway staffTo prevent traffic accidents
Rarely linked to watershed Management issues
Roadside Ditch Program
RESEARCH Objectives:
• How do different ditch management practices affect the quantity and type of materials movinginto streams (TSS, bedload, dissolved chemicals, water)?
2) What percentage of the total stream load and flow is contributed by the network of ditches in a watershed?
3) Can we develop a model that estimates ditch loadingsbased on internal or external land use characteristics?
EXTENSION Objectives:
1) Build awareness of the issue and alternative managementpractices for town highway staff and town planners.
2) Educate youth about ditches and how they affect streams.
ENFIELD6-MILE
DOOLITTLE
Susquehanna R.
Cayuga Lake
exposed
vegetated
stream
Station type:
Research Study Sites
8 SamplingStations +
Creek
Site 4
Site 2
Site 6
Site 1
• Total water flow• Suspended sediment• Dissolved chemicals
• Bedload sediment
8 ReplicateSampling Stations
+ Creek
ResearchDoolittle, Enfield,
6-Mile Creeks
Ditches: 142 km70% linked to stream,largely in 1st order,headwaters.
Stream Channel Density1.6 km-1 to 4.1 km-1
Enfield Creek
Road length 87 km
Stream length 88 km
Divide 56 km 2 in size
Vegetated
Scraped, exposed
Preliminary Findings
00.40.81.21.6
22.42.83.23.6
44.44.8
Pea
k co
ncen
tratio
nof
TS
S (g
/L)
0 8.3 13.7 41.7 64.3 71.7 90.2 97.5 100
Percent of Scrapedor exposed substrate
12345 (f5 (t678
Ditch #
Suspended sediment loadsare significantly higher from
scraped ditches.
Significant quantitiesof bedload transportmove in scraped andexposed ditches.
Roadside Ditch Impacts
1) Mechanism for increasedland-water linkages
2) Intercept and divert runoffrapidly to stream.
3) Internal source of sediment and other contaminants
Recommendation:Don’t scrape ditches and leavethem exposed to erosion duringstorm events.
Extension To Town Highway Dept. and
Town Planners
17 presentations to 1000 stakeholders
Recommendation:Use infiltration Basins / Detention Ponds to capture water and allow it to recharge groundwater
K-12 Curriculum on Roadside Ditches: students learn to use GPS and map their ditches on the Website
http:// ei.cornell.edu/watersheds/ditches