CONSERVATION STRATEGY
FOR WATER QUALITY IN THE
UPPER CAPE FEAR
WATERSHEDDeveloping a Conservation Strategy for the Upper Cape Fear
Triangle Land Conservancy
Goals
Develop an integrated one water system that builds support for Source Water Protection through land conservation in addition to other strategies
Recap Successes in the Upper Neuse
Present GIS Model & Implications for the Jordan Lake Watershed
TLC Mission
TLC strives to create a healthier and more vibrant
Triangle region by safeguarding clean water,
protecting natural habitats, supporting local farms
and food, and connecting people with nature
through land protection and stewardship, catalyzing
community action, and collaboration.
Safeguarding Clean Water
RESULTS:
• An additional 5,000 acres of land in
the Neuse River basin is protected in
collaboration with cities of Raleigh,
Durham and nonprofit partners.
• An additional 2,000 acres of land is
protected in Cape Fear basin with
government, nonprofit and other
partners.
4
Outcome: Priority lands in
watersheds identified &
permanently protected.
Priority Areas:Where conservation value meets “leverage.”
What exactly is land conservation?
Conservation Easements Certain development rights are sold or donated
Fee Simple Purchase Land purchased outright
All actions are voluntary Requires strong relationships with land owners
Land managed to maximize conservation values.
UNCWI Accomplishments
111Miles of
stream
114Properties
10413Acres of
land
N5700 lbs
P1000 lbs
Value of property protected
$91,840,650
Value donated by landowners
$22,621,930
Invested by Raleigh $13,878,670
Raleigh leverage ratio $7 : $1
10,000+ acres
$0.15 per 1000 gallons
($0.11 per CCF)
Durham Water Management
• Watershed Protection Plan creates an objective process for directing funds
• Establishes a mechanism to collaborate with UNCWI:• Leverages City of Durham
funding
• Enables watershed protection outside of Durham County
• Provides land management and monitoring
• In 2011, Council approved 1¢ per tier dedicated
Upper Cape Fear Watershed
52.3%
23.8%
20.9%
2.5% 0.6%
Forests
Agriculture
Developed
Open Water
Wetlands
GIS Model: What Should be Protected?
Overall Goal: Identify the areas we don’t want to lose
What areas are most important to maintaining water quality? Based on available knowledge and data
Land Conservation is opportunistic Which opportunities should be seized? Where should we focus relationship building with
land owners?
Screening Tool Looking for Parcels Scoring above the median
GIS Model Overview
}
Original Data
Layers
Objective
Scores
Goal
Scores
}+
Model
Score
+
+
Analysis Scale
Raster:
Grid of 30-m cells
Catchments:
1-100 acres
30*30
Conservation Goals
Protect Water Sources and Conveyances
• Protect Headwater Streams
• Protect Riparian Areas
• Connect Protected Waters
Protect Pervious Uplands
• Protect pervious landcover
• Protect Pervious Catchments
• Protect forests
Promote Water Infiltration and Retention
• Protect Wetlands
• Protect Floodplains
• Protect Infiltrating Soils
Vulnerable Areas
• Protect wet/hydric areas
• Protect steep slopes
• Protect erodible soils
Goal #1: Protect Water Sources & Conveyances
Objective Assessment
1.1 – Protect Headwater
Streams and Catchment
Catchment Flow Accumulation
1.2 – Protect Riparian Areas
and Shorelines
Distance from Streams &
Waterbodies
1.3 – Support and Protect
Connected Water Features
% of Catchment with Existing
Protection
10- Headwater Stream 0- Not a headwater stream
1.1 Headwater Streams
Rationale: Small streams at the top of the basin are more sensitive and affect water quality far downstream.
Identification: Selected catchments with no upstream neighbor
Objective 1.2:
Connect Protected Water Features
Rationale: Focusing conservation in catchments with existing protected areas will enhance the conservation value of existing and additional protection.
Identification: Select catchments with a high percentage of land already protected
Objective 1.3 Protect
Riparian Areas & Shorelines
Rationale: Stream and lakeside buffers provide stability, prevent erosion, trap sediments and nutrients, and attenuate flooding
Identification: Select areas based on distance to streams, lakes and ponds.
Goal #2: Conserve Upland Areas
Objective Assessment
2.1 – Protect Pervious
Upland Areas
Land Use / Land Cover (LULC)
1.2 – Protect Catchments
with Minimal Impervious
Areas
Catchment Imperviousness,
calculated from LULC
1.3 – Protect Forested
Catchments
% of Catchment Forested
Objective 2.1:
Protect Pervious Upland Areas
Rationale: Pervious areas will generate less runoff and contribute fewer nutrients and sediment to water bodies.
Identification: Based on Land Use / Land Cover
Objective 2.2: Protect Catchments
with Minimal Imperviousness
Rationale: Impervious surfaces generate more runoff and pollutants within a catchment.
Identification: Calculate Imperviousness from Land Use / Land Cover
Objective 2.3: Protect
Forested Catchments
Rationale: Forests retain and process water, nutrients and sediment. Forest cover has been linked to higher water quality and lower treatment costs.
Identification: Select catchments with a high percentage of forested area
Goal #3: Promote Infiltration & Retention
Objective Assessment
2.1 – Protect Wetlands Contains or is within 50 ft. of a
wetland
1.2 – Protect Floodplains Within FRIS designated
floodplain
1.3 – Promote Soil
Infiltration
Soil hydrologic group
Objective 3.1:
Protect Wetlands
Rationale: Wetlands process nutrients and sediment and attenuate flooding.
Identification: Areas near wetlands (< 50 ft.) based on National Wetlands Inventory & LULC
Objective 3.2:
Protect Floodplains
Rationale: Floodplains process nutrients and sediment and attenuate flooding. Development in floodplain would be hazard prone.
Identification: Within FRIS determined flood risk zones.
Objective 3.3:
Protect Groundwater Recharge
Rationale: Groundwater recharge reduces flooding and the transport of nutrients and sediment.
Identification: Areas with high soil infiltration rates based on their Hydrologic Group
Goal #4: Protect Vulnerable Areas
Objective Assessment
4.1 – Protect Frequently Inundated
Areas
Hydric Soils
4.2 – Protect Steep Slopes Slope
4.3 – Protect Erodible Soils Soil K Factor
Objective 4.1:
Protect Inundated Areas
Rationale: Water naturally accumulates in wet areas. Development in these areas will exacerbate flooding.
Identification: Areas with hydric soils
Objective 4.2:
Protect Steep Slopes
Rationale: Steep slopes are more susceptible to erosion caused by development
Identification: Slope determined using LiDAR elevation map
Objective 4.3:
Protect Erodible Soils
Rationale: Development on erodible soils will generate higher sediment runoff
Identification: Areas with highly erodible soils based on soil texture and stickiness (K-factor)
Weighting example
A pixel scoring 4 on one objective and
10 on a second objective
would have a goal score of 7 if the
objectives were weighted equally…
(50% x 4) + (50% x 10) = 2 + 5 = 7
…and a goal score of 8.5 if the first
objective was weighted at 25% and the
second at 75%.
(25% x 4) + (75% x 10) = 1 + 7.5 =
8.5
Objective Weighting
9 x each color
Divide your stickers among the objectives according to their importance to the model goal to which they
belong.
Objectives are color-coded by goal to match the sticker colors; place stickers on matching objective sheets.
Weighting Model Goals
Divide your 16 orange stickers among the 4 model goals according to their importance to preserving drinking water quality.
x16
Combining Goals
UNCWI Model Weighting
Jordan Lake stakeholder weighting
Goal Weight JLOW
1 – Protect Water Sources &
Conveyances
29%
2 – Protect Pervious Uplands 31%
3 – Promote Infiltration &
Retention
19%
4 – Protect Vulnerable Areas 21%
Model Results & Implications
Ran Model w/ “UNCWI Weighting”
Calculated average score for parcels > 10 acres
Isolated “Priority Parcels” scoring above mean 13,124 Parcels spanning 425,000+ acres (39% of Watershed)
4,138 Parcels in FRIS floodplain; 28,000+ floodplain acres
Next Steps?
Rerun model with todays weights
Development of Report and online tool
Continue build support for land conservation as a component of a one water initiative for the area
Develop benefit metrics- nutrient and risk scenarios
Outreach to local leaders and boards
Develop resources and strategies to incorporate land protection as a BMP
Develop a water fund in the watershed
Questions?
Leigh Ann Hammerbacher
Senior Associate Director of Conservation
P: 919.908.0060
Ryan Parks
Conservation Intern | Duke MEM
P: 512.569.5843
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