Subwatershed Planning TMDLs
-
Upload
choose-clean-water -
Category
Education
-
view
701 -
download
0
description
Transcript of Subwatershed Planning TMDLs
Subwatershed Planningin Calvert County Maryland
Prepared for the
1st Annual Choose Clean Water –
Chesapeake Bay Restoration Conference
A Clean‐up for the Bay – What to
Expect from the Bay TMDLs at the local level
• TMDL effect on the planning process• TMDL integration with WRE of Comp
Plans• Engaging stakeholders• Eventual implementation of pollution
reduction measures
3
September 15, 2008
Water Resource Element
A. Analyze long‐term water needs and supplies
B. Analyze the impact of sewer treatment plants
C. Analyze the impact of stormwater (diffuse sources)
HB 1141: Water Resources
But first of all, where are we?
Calvert CountyWatersheds
6
Entire Watershed –Selected Data
Land Use Zoning
Patuxent Tributary Goals
7Maryland Tributary Strategy Patuxent River Basin, Summary Report for 1985-2005 Data, August 2007
8
Water Quality:Patuxent River Basin
HB 1141: Water Resources
9Maryland Tributary Strategy Patuxent River Basin, Summary Report for 1985-2005 Data, August 2007
10Maryland Tributary Strategy Patuxent River Basin, Summary Report for 1985-2005 Data, August 2007
11
Maryland Tributary Strategy Patuxent River Basin, Summary Report for 1985-2005 Data, August 2007
12
Water Quality: Fresh Water Stream Survey
HB 1141: Water Resources
13
Maryland Biological Stream Survey 2000-2004 County Results
Riparian Buffers
14
Maryland Biological Stream Survey 2000-2004 County Results
Physical Habitat Index
15
Maryland Biological Stream Survey 2000-2004 County Results
Nitrate-Nitrogen
16
Maryland Biological Stream Survey 2000-2004 County Results
Total Phosphorus
Water Quality: Based on Land Use and Pollutant Loads
HB 1141: Water Resources
17
19
Impervious Surfaces
Most of our subwatersheds have less than 5% impervious surfaces.
Two subwatersheds would be considered ‘urban’ (more than 10% impervious surfaces.)
Forest canopy is 56-58%.
60% is considered good.
20
So what can we conclude from the data?
• Our nutrient loads are higher than we want.• Erosion has caused significant stream damage in places.
• There are opportunities for good water quality• Impervious surfaces are still low and forest cover is still high in most watersheds.
HB 1141: Water Resources
21
Smart Growth• Priority
Preservation Areas• Priority Funding
Areas• Transition areas
HB 1141: Water Resources
Best Management Practices (BMPs) and Projected Growth -Nitrogen
Total Nitrogen Load
0200,000400,000600,000800,000
1,000,0001,200,000
2007 LU,2002
BMPs
2007 LU,Trib Strat
BMPs
Scenario1 TribStrat
BMPs
Scenario2 TribStrat
BMPs
Lbs/
Yr Total Septic LoadTotal Terrestrial Load
23
HB 1141: Water Resources
Best Management Practices (BMPs) and Projected Growth -Phosphorus
Total Phosphorus Load
010,00020,00030,00040,00050,00060,00070,000
2007 LU,2002
BMPs
2007 LU,Trib Strat
BMPs
Scenario1 TribStrat
BMPs
Scenario2 TribStrat
BMPs
Lbs/
Yr
Total Phosphorus Load
24
Best Management Practices include: Cover Crops . . . .
Non-structural stormwater
management
Non-structural stormwater
management
HB 1141: Water Resources
Best Management Practices BMPs and Projected Growth –Impervious Cover
Total Impervious Cover
02,0004,0006,0008,000
10,00012,000
2007 LU,2002
BMPs
2007 LU,Trib Strat
BMPs
Scenario1 TribStrat
BMPs
Scenario2 TribStrat
BMPs
Acre
s
Total Impervious Cover
29
HB 1141: Water Resources
Best Management Practices BMPs and Projected Growth –Forest and Agriculture
Forest and Agriculture
010,00020,00030,00040,00050,00060,00070,00080,00090,000
2007 LU,2002 BMPs
2007 LU,Trib Strat
BMPs
Scenario 1Trib Strat
BMPs
Scenario 2Trib Strat
BMPs
Acre
s ForestAgriculture
30
Proposed Stormwater Actions(diffuse sources)
HB 1141: Water Resources
31
32
•Set water quality goals. •Prepare subwatershed plans.•Continue to monitor water quality.•Include tree ordinances, with tree canopy goals, in all town center ordinances.•Update the stormwater management ordinance.
HB 1141: Water Resources
Include the following:
33
By what standards should we measure water quality?
Draft goals for fresh water:
• <0.71 milligrams of nitrogen per liter
• <0.031 milligrams of phosphorus per liter
• <10 TNUs of turbidity
Draft goals for tidal water:
• Chlorophyll <10 micrograms per liter of water
• Secchi Depth measurements > 1 meter
•Oxygen levels: 4 mg/l for deep waters and 6 mg/l for surface waters.
35
Draft goals for urban subwatersheds > 10% impervious:
•Maintain swimmable/ fishable water quality;•Improve water clarity by reducing sedimentation;•Restore aquatic diversity in freshwater streams;•Increase groundwater recharge;•Enhance waterfront access.
36
Draft goals for rural subwatersheds < 10% impervious:
Achieve the goals of the urban subwatersheds, plus the following:
•Maintain or restore anadromous (fish spawning) streams•Develop and maintain shellfish beds, both sanctuary and open to harvesting.
Subwatershed Master Plans• Build Partnerships • Characterize Subwatershed• Finalize Goals and Identify
Solutions• Design Implementation
Program• Implement Watershed Plans• Measure Progress and make
adjustments.
Mill Creek:
One of two urban subwatersheds in Calvert County
Town Centers:
Stormwater from two town centers flow toward Mill Creek
Zoning
-Town Center-Residential-Employment Center
Land Use
-Commercial-Residential-Public-Undeveloped
Contour Map
The upper reaches of the subwatershed contain steep slopes
Tree Coverage
Approximately 40% of the subwatershed has tree coverage
-Served by Solomons Sewer System-Served by traditional septic systems-Served by nitrogen-removing system
Sewer vs. Septic
Test sites
Annual harbor study and the Lower Restoration Action Strategy
First Five Subwatershed
Plans
• Hall Creek• Fishing Creek• Parker’s Creek• Gray’s Creek• Mill Creek
Building connections with citizens
We have been:
• Collecting email addresses at public presentations
• Collecting email addresses at community meetings
• Notifying citizens of meetings via email• Posting PowerPoints and videos on the web.
48
Challenges
• Creating walkable communities while protecting water quality.• Developing mitigation strategies.• Paying for infrastructure needed for smart growth.• Determining the most cost effective tools to achieve nutrient reduction.• What to do first?