South Branch Patapsco River Watershed
Characterization Plan
Spring 2016
Prepared by
Carroll County Bureau of Resource Management
South Branch Patapsco Watershed Characterization Plan
Table of Contents
List of Figures................................................................................................................................ iv List of Tables ................................................................................................................................. iv List of Appendices .......................................................................................................................... v List of Acronyms ........................................................................................................................... vi
I. Characterization Introduction ................................................................................................. 1
A. B. C.
Purpose of the Characterization ....................................................................................... 1 Location and Scale of Analysis........................................................................................ 1 Report Organization......................................................................................................... 3
II. Natural Characteristics............................................................................................................ 5
A. B. C.
Introduction...................................................................................................................... 5 Climate ............................................................................................................................. 5 Physical Location............................................................................................................. 7
Topography................................................................................................................... 7 Soils ............................................................................................................................ 10
Hydrologic Soil Groups.......................................................................................... 10
Geology ...................................................................................................................... 13
Surface Water Resources ............................................................................................... 15
Wetlands..................................................................................................................... 15 Floodplains ................................................................................................................. 18 Forest .......................................................................................................................... 20
Forest Cover............................................................................................................ 20
Ecologically Important Areas......................................................................................... 22 Groundwater Resources ................................................................................................. 24
1. 2. a.
- III.
- Human Characteristics...................................................................................................... 25
Population....................................................................................................................... 25 Baseline and Current Land Cover.................................................................................. 25 Priority Funding Areas, Zoning and Build Out.............................................................. 28
Priority Funding Areas ............................................................................................... 28 Zoning and Build-Out................................................................................................. 28
Impervious Surfaces....................................................................................................... 32 Stormwater ..................................................................................................................... 34
Stormwater Management Facilities............................................................................ 34 Storm Drain Systems.................................................................................................. 35
Drinking Water............................................................................................................... 37
Wellhead Protection Areas ......................................................................................... 37 Public Water Service Area ......................................................................................... 37 Water Supply.............................................................................................................. 37
Wastewater..................................................................................................................... 39
Public Wastewater Service Area ................................................................................ 39 Wastewater Discharge Locations ............................................................................... 39 On-Site Septic Systems .............................................................................................. 40
A. B. C.
1. 2.
D. E.
1. 2.
F.
1. 2. 3.
G.
1. 2. 3.
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South Branch Patapsco Watershed Characterization Plan
H. I.
NPDES Point Sources.................................................................................................... 42 Protected Lands.............................................................................................................. 43
Rural Legacy Program................................................................................................ 43
Agricultural Best Management Practices....................................................................... 47
Farm Plan Acres ......................................................................................................... 47
1. 1.
J.
- IV.
- Water Quality.................................................................................................................... 49
Introduction.................................................................................................................... 49 Designated Uses ............................................................................................................. 49 Tier II Waters ................................................................................................................. 50 Total Maximum Daily Loads......................................................................................... 50
Current Impairments................................................................................................... 50
Water Quality Data......................................................................................................... 52
Current Monitoring..................................................................................................... 52 Maryland Biological Stream Survey .......................................................................... 54
A. B. C. D.
1.
E.
1. 2.
- a.
- Maryland’s DNR Results........................................................................................ 54
V. Living Resources .................................................................................................................. 59
A. B.
Introduction.................................................................................................................... 59 Aquatic Biology ............................................................................................................. 59
Index of Biotic Integrity ............................................................................................. 60
Maryland’s DNR Results........................................................................................ 60
1. a.
- b.
- Carroll County Results............................................................................................ 62
D.
Sensitive Species............................................................................................................ 66
Rare, Threatened and Endangered Species................................................................. 66
Stream Corridor Assessment.......................................................................................... 66
Subwatershed Summary ............................................................................................. 71
1. 1.
- VI.
- Characterization Summary................................................................................................ 73
Summary ........................................................................................................................ 73 Cost Summary................................................................................................................ 73
A. B.
VII. References:........................................................................................................................ 74
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South Branch Patapsco Watershed Characterization Plan
List of Figures
Figure 1-1 South Branch Patapsco Watershed Location Map........................................................ 2 Figure 2-1 South Branch Patapsco Subwatershed Locations ......................................................... 6 Figure 2-2 South Branch Patapsco Watershed Topography and Slope Categories........................ 9 Figure 2-3 South Branch Patapsco Watershed Hydrological Soil Groups................................... 12 Figure 2-4 South Branch Patapsco Watershed Geology............................................................... 14 Figure 2-5 South Branch Patapsco Watershed Wetland Acreage ................................................ 17 Figure 2-6 South Branch Patapsco Watershed Floodplains ......................................................... 19 Figure 2-7 South Branch Patapsco Watershed Forest Cover........................................................ 21 Figure 2-8 South Branch Patapsco Watershed Green Infrastructure............................................ 23 Figure 3-1 South Branch Patapsco Watershed Land Use and Land Cover .................................. 27 Figure 3-2 South Branch Patapsco Watershed Priority Funding Areas ....................................... 29 Figure 3-3 South Branch Patapsco Watershed Zoning................................................................. 30 Figure 3-4 South Branch Patapsco Watershed Build-Out Parcels................................................ 31 Figure 3-5 South Branch Patapsco Watershed Impervious Surface Area .................................... 33 Figure 3-6 South Branch Patapsco Watershed Stormwater Management Facilities .................... 36 Figure 3-7 South Branch Patapsco Watershed Public Drinking Water Supply............................ 38 Figure 3-8 South Branch Patapsco Watershed Wastewater Service Area.................................... 41 Figure 3-9 South Branch Patapsco Watershed Protected Lands .................................................. 45 Figure 3-10 South Branch Patapsco Watershed Rural Legacy Area ............................................ 46 Figure 3-11 South Branch Patapsco Watershed Agricultural BMP Locations............................. 48 Figure 4-1 South Branch Patapsco Watershed Tier II Water Segments....................................... 51 Figure 4-2 Shannon Run Monitoring Station................................................................................ 53 Figure 4-3 South Branch Patapsco Watershed DNR MBSS Locations ....................................... 55 Figure 5-1 South Branch Patapsco Watershed Carroll County MBSS Locations........................ 65 Figure 5-2 South Branch Patapsco Watershed Targeted Ecological Areas.................................. 68 Figure 5-3 SCA Landowner Participation .................................................................................... 69 Figure 5-4 Most Commonly Identified Impacts ........................................................................... 70
List of Tables
Table 1-1 South Branch Patapsco Watershed’s Subwatershed Acreages ..................................... 3 Table 2-1 South Branch Patapsco Watershed Slope Categories................................................... 8 Table 2-2 South Branch Patapsco Subwatershed Hydrologic Soil Group Categories................ 11 Table 2-3 South Branch Patapsco Watershed Wetland Acreage ................................................ 16 Table 2-4 South Branch Patapsco Watershed Forest Cover........................................................ 20 Table 3-1 South Branch Patapsco Watershed Baseline and Current Land Cover....................... 26 Table 3-2 South Branch Patapsco Watershed Estimated Impervious Surface Area ................... 32 Table 3-3 South Branch Patapsco Watershed Stormwater Facility Types.................................. 34 Table 3-4 South Branch Patapsco Watershed NPDES Permits .................................................. 42 Table 3-5 South Branch Patapsco Watershed Protected Lands .................................................. 43 Table 4-1 Water Quality Parameters and Methods ................................................................... 52 Table 4-2 South Branch Patapsco Watershed DNR’s MBSS Chemical Results ........................ 56 Table 4-3 South Branch Patapsco Watershed DNR’s MBSS Chemical Results Summary........ 58
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South Branch Patapsco Watershed Characterization Plan
Table 5-1 South Branch Patapsco Watershed DNR’s MBSS Index of Biotic Integrity ............. 60 Table 5-2 South Branch Patapsco Watershed Carroll County MBSS Benthic IBI ..................... 62 Table 5-3 Stream Corridor Assessment – Identified Impacts...................................................... 67 Table 5-4 Linear Feet of Inadequate Buffer and Stream Erosion................................................ 71
List of Appendices
Appendix A South Branch Patapsco Watershed Stormwater Management Facilities ................ 75 Appendix B Agricultural Best Management Practices ................................................................ 86
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South Branch Patapsco Watershed Characterization Plan
List of Acronyms
- BMPs
- best management practices
COMAR Code of Maryland Regulations DNR EPA FEMA GIS
Maryland Department of Natural Resources United States Environmental Protection Agency Federal Emergency Management Agency geographic information system
HSG IBI hydrological soil group Index of Biotic Integrity
MBSS MDE NLCD
Maryland biological stream survey Maryland Department of the Environment National Land Cover Database
NPDES national pollution discharge elimination system
- PFA
- priority funding area
RTE SW rare, threatened or endangered stormwater
TMDL TSS USDA WLA total maximum daily load total suspended sediments United States Department of Agriculture wasteload allocation
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South Branch Patapsco Watershed Characterization Plan
- I.
- Characterization Introduction
- A.
- Purpose of the Characterization
The South Branch Patapsco Watershed Characterization Plan is intended to provide a background on the hydrological, biological and other natural characteristics of the watershed as well as discuss human characteristics that may have an impact within the watershed. The information provided in this report as well as information gathered during the South Branch Patapsco Watershed stream corridor assessment (SCA) will be used as a tool to help direct the watershed implementation plan for the South Branch Patapsco Watershed. The implementation plan will be used to identify opportunities for water quality improvements within the watershed
as required by the County’s National Pollutant Discharge Elimination System (NPDES) permit,
and is designed to meet approved Total Maximum Daily Loads (TMDLs) for the South Branch Patapsco Watershed.
- B.
- Location and Scale of Analysis
The South Branch Patapsco Watershed is located in southern portion of Carroll County, Maryland. The South Branch Patapsco Watershed is within the Piedmont Plateau Province of Maryland. The Piedmont Plateau province is characterized by gentle to steep rolling topography, low hills, and ridges (MGS 2009). The watershed area within Carroll County covers 38,736 acres within eleven sub-watersheds. Figure 1-1 depicts the location of the South Branch Patapsco Watershed and the several subwatersheds within Carroll County. The South Branch Patapsco Watershed drains to the Patapsco River Lower North Branch, which is a tributary to the Chesapeake Bay. Table 1-1 displays the distribution of acreage between the subwatersheds within South Branch Patapsco Watershed. The analyses presented in this report are done at the subwatershed scale. This allows for restoration and preservation efforts to be focused on smaller drainage areas where efforts can be prioritized and more easily monitored.
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South Branch Patapsco Watershed Characterization Plan
Figure 1-1: South Branch Patapsco Watershed Location Map
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South Branch Patapsco Watershed Characterization Plan
Table 1-1: South Branch Patapsco Watershed’s Subwatershed Acreages
DNR 12-digit Scale
021309081031 021309081030 021309081029 021309081021 021309081023 021309081024 021309081028 021309081025 021309081022 021309081020 021309081026
Subwatershed Gills Falls Upper
Acres
3,118.40 4,243.17 3,781.73 2,306.82 8,007.30 1,442.79 3,169.38 4,116.38 1,953.15 1,430.57 5,166.27
38,735.95
Gills Falls Lower
Middle Run
Piney Run Lower Piney Run Main
Piney Run Tributary South Branch Patapsco
South Branch Patapsco River South Branch Patapsco River South Branch Patapsco River
Tuckers Branch
South Branch Patapsco Watershed Total Report Organization
This report is organized into six different chapters: