conservation strategy for water quality in the … quality/planning... · continue build support...

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

E: lhammerbacher@triangleland.org

P: 919.908.0060

Ryan Parks

Conservation Intern | Duke MEM

E: ryan.parks@duke.edu

P: 512.569.5843