RIPARIAN BUFFER PRESERVATION AND STREAMBANK RESTORATION IN THE UPPER NEUSE RIVER BASIN: A BLUEPRINT FOR THE FUTURE

Transcription

1 RIPARIAN BUFFER PRESERVATION AND STREAMBANK RESTORATION IN THE UPPER NEUSE RIVER BASIN: A BLUEPRINT FOR THE FUTURE A Report to the North Carolina Clean Water Management Trust Fund By: TRIANGLE J COUNCIL OF GOVERNMENTS In Partnership With The Upper Neuse River Basin Association June 30, 2000 This project was funded, in part, through a grant from the North Carolina Clean Water Management Trust Fund.

2 RIPARIAN BUFFER PRESERVATION AND STREAMBANK RESTORATION IN THE UPPER NEUSE RIVER BASIN: A BLUEPRINT FOR THE FUTURE Table of Contents Acknowledgements Page iii Purpose 1 Overview of the Upper Neuse River Basin and Importance of its Riparian Buffers 1 The Extent and General Character of Riparian Corridors in the Upper Neuse Basin 7 Evaluation of Existing Local and State Riparian Buffer Requirements 11 Riparian Buffer Protection Goals 14 Need for Buffer and Streambank Improvements Plan for the Upper Neuse Basin 16 Riparian Buffer and Streambank Protection Information Management System 16 Building Partnerships to Promote Riparian Buffer Protection and Restoration 18 For More Information 24 List of Figures Figure 1. Upper Neuse River Basin: Watershed Management Units 2 Figure 2. Upper Neuse River Basin: Use Support Ratings for Evaluated Streams 6 Figure 3. Estimated Total Area of Potentially Polluting Land Uses as a % of Total 9 Area, By 14-Digit Hydrologic Unit Figure 4. Upper Neuse River Basin: NPS Potential 10 Figure 5. Relative Potential for Reforestation of 330-Foot Riparian Corridor 12 Figure 6. Estimated % Imperviousness, By 14-Digit Hydrologic Unit 13 Figure 7A and 7B. GIS map analysis view and associated photograph of Ellerbe 19 Creek, adjacent to Hillandale Golf Course Figure 8A and 8B. GIS map analysis view and associated photograph of 20 S. Lowell Road area Figure 9A and 9B. GIS map analysis view and associated photographs of 21 St. Mary s Road and Schley Road area Figure 10A and 9B. GIS map analysis view of Lake Holt and associated 22 photograph of tributary pond draining unforested area Figure 11A and 11B. GIS map analysis view of Lake Rogers Watershed and 23 associated photograph of watershed tributary Figure 12. ArcView software screen view of parcels, non-forested riparian 24 Corridors, and streams, with associated hot-linked photograph i

3 Table of Contents (continued) Figure A-1. Priority Protection Areas- Goal 1: Water Quality Figure A-2. Priority Protection Areas- Goal 2: Ecosystem Integrity Figure A-3. Priority Protection Areas- Goal 3: Recreational and Educational Use Figure A-4. Priority Protection Areas- Goal 4: Loss of Life/ Property Damage Prevention Figure A-5. Priority Protection Areas- Environmental, Resource, & Hazard Mitigation Value: Goals 1 4 Composite Figure A-6. Non-Forested Areas Within the 330-Foot Riparian Zone Page (In Pocket Folder) (In Pocket Folder) (In Pocket Folder) (In Pocket Folder) (In Pocket Folder) (In Pocket Folder) List of Tables Table 1. Land Area and Major Features of 14-Digit Hydrologic Units 3 Table 2. Twenty Benefits of Urban Stream Buffers 5 Table 3. Land Area, Primary Surface Waters, and Estimated Stream Miles, 8 By 14-Digit Hydrologic Units Table 4. Summary Listing of Attributes Used in Prioritization Model, and 15 Respective Weights of Attributes By Major Goal Table 5. Expected Local Government Funding for Riparian Buffer Protection 17 And Restoration Efforts and Greenway Development Within the Upper Neuse River Basin Appendices TJCOG Technical Memo: Riparian Buffer Series, No. 1 An Introduction to Riparian Buffers TJCOG Technical Memo: Riparian Buffer Series, No. 2 A Summary of Selected Riparian Buffer Models (In Pocket Folder) (In Pocket Folder) TJCOG Technical Memo: Riparian Buffer Series, No. 3 (In Pocket Folder) Prioritizing Riparian Buffers for Protection and Restoration TJCOG Technical Memo: Riparian Buffer Series, No. 4 Local Ordinances for Protecting Riparian Buffers (In Pocket Folder) ii

4 Acknowledgements This project was funded, in part, through a grant from the North Carolina Clean Water Management Trust Fund. Triangle J Council of Governments (TJCOG) expresses deep appreciation to the Trust Fund for the support provided for this effort. The work reported here represents the efforts of many individuals listed below who have participated in the Upper Neuse River Basin Riparian Buffer Study Committee. TJCOG s acknowledges the support provided by several agencies relating to the compilation of the many geographic information systems coverages used in this effort. Some of those agencies were: the North Carolina Center for Geographic Information and Analysis; the U.S. Environmental Protection Agency s Landscape Characterization Spatial Analysis Laboratory (Research Triangle Park, North Carolina); the North Carolina Division of Water Quality; and the member governments of the Upper Neuse River Basin Association. Members of the Upper Neuse River Basin Riparian Buffer Study Committee Janice Allen Diana Lewis Rick Bailey Wright Lowry Lee Billington Annette Lucas Brad Boris Keith Luck Sue Burke Lisa Martin Patrick Byker Syd Miller Wayne Cash Bonnie Nobori Pete Colwell Kate Dixon Brian Dobyns Dr. John Parsons Bill Flournoy LeiLani Paugh Moreland Gueth Kay Pearlstein Ed Harrison Linda Pearsall Margaret Hauth Scott Pohlman Tanner Holland Steve Reed Craven Hudson Terry Rolan Danny Johnson Rick Seekins Tom King Jean Spooner Ken Kirby Dave Stancil Jane Korest Perry Sugg Staff support to the Committee was provided by TJCOG staff (Patrick Davis, Ben Hitchings, and Jeff Essic). Geographic information systems support and map production was accomplished primarily by Jeff Essic, TJCOG s MIS/GIS Coordinator. iii

5 Purpose The purpose of this report to summarize the work completed under the Upper Neuse River Basin Riparian Buffer Study project, which has been funded in part by the North Carolina Clean Water Management Trust Fund. Triangle J Council of Governments (TJCOG) has served as the lead agency. The report includes sections that: (a) address the extent of riparian buffer corridors and an analysis of general riparian buffer conditions in the watershed; (b) summarize local government requirements relating to riparian buffer protection; (c) describe the Upper Neuse River Basin Riparian Buffer Prioritization Model; (d) outline local government funding anticipated to be available for open space protection and greenways development in the Upper Neuse River Basin; and (e) describe the Upper Neuse River Basin Riparian Buffer Information Management System. It is hoped that this study will: (a) be of assistance to public and private decision-makers as they work together to maximize the benefit from technical and financial resources that are available for riparian buffer protection and restoration in the Upper Neuse River Basin; (b) provide a foundation for an integrated and ongoing riparian buffer protection strategy for the watershed; (c) support the Upper Neuse Watershed Management Plan preparation project now underway by the Upper Neuse River Basin Association; and (d) provide useful information and a model approach for regional green infrastructure protection efforts. Overview of the Upper Neuse River Basin and Importance of Its Riparian Buffers The Upper Neuse River Basin (Neuse River Sub-basin ) is a 770-square mile watershed located above the Falls Lake Dam, in the northeastern Piedmont region of North Carolina. This watershed is comprised of 28 different 14-digit hydrologic units (3 of which comprise the surface area of Falls Lake), as shown on Figure 1 and summarized in Table 1. Six counties and eight municipalities have planning and zoning jurisdiction in the watershed (Counties are: Durham, Franklin, Granville, Orange, Person and Wake. Municipalities are: Butner, Creedmoor, Durham, Hillsborough, Raleigh, Roxboro, Stem and Wake Forest). Each of these local governments participates in the Upper Neuse River Basin Association (UNRBA), an organization that provides a forum for local governments to work together to address water resource planning, management and protection issues of mutual concern. Among the issues of interest to the UNRBA are: the protection of water supply water quality; the restoration of impaired waters; and the management of riparian buffers within the watershed. TJCOG provides support services and assistance to the UNRBA s Executive Director and Board of Directors. The Upper Neuse River Basin contains nine man-made reservoirs that serve as the drinking water supply sources for approximately 500,000 people. The watershed also contains many surface waters that are essential for a diverse and large population of terrestrial and aquatic plants and animals and that provide important recreational benefits. The health of the reservoirs and the many miles of streams and rivers within the watershed is essential to the public health, quality of life, and economic vitality of the rapidly growing Research Triangle region. Conversely, the health of the watershed is dependent upon how public and private decision-makers use, manage and protect the land within the watershed. 1

6 Figure 1. Upper Neuse River Basin: Watershed Management Units NF lat R S Flat R B Falls of the Neuse Res. Eno R y Cr Ston Upper Eno River Watershed r bee C Eller Cr L Lick r kc Lic Legend Primary Upland Water Supply Watersheds Cr on art B U Cr on art B L 14-Digit Watershed Management Unit Boundaries* B r er C nth Pa UNRBA Sub-Hydrologic Units# Ho rse Cr B Lig ht Cr B Cr B Little R Eno R A Ne w Cr Ce da rc r Sevenmile A Ledge Cr A R Eno Lake Rogers Watershed S Fk Little R For rest Cr Str ou d's Ck Flat R or En Fk A Cr ds Ree R Eno W tr Fla E Fk NF kl ittl er Lake Holt Watershed Knap of Little River Watershed Be av erd am r kc hy F Bus Deep Cr Cr ge rid de Al Lake Michie Watershed Streams Water Bodies N * All Hydrologic Unit Numbers shown begin with W # Sub-units are designated by the Upper Neuse River Basin Association E S Triangle J Council of Governments Geographic Information System June, Miles 2

7 Table 1. UPPER NEUSE RIVER BASIN: LAND AREA AND MAJOR FEATURES OF 14-DIGIT HYDROLOGIC UNITS 14-Digit Hydrologic Land Area Unit Code Acres Sq. Mi. Primary Surface Waters , North Flat River, Chappels Creek , South Flat River, Alderidge Creek, Bushy Fork Creek , Flat River , Deep Creek, Rock Fork Branch , Lake Michie, Flat River, Dry Creek, Dial Creek , North Fork Little River, Buffalo Creek , South Fork Little River, Forrest Creek , South Fork Little River , Little River Reservoir, Little River , Lake Orange, West Fork Eno River, East Fork Eno River , McGowans Creek, Sevenmile Creek, Lake Ben Johnson , Eno River, Strouds Creek, Stoney Creek , Eno River, Crooked Creek , Eno River , Lake Butner (Holt), Knap of Reeds Creek, Camp Creek , Knap of Reeds Creek , Ellerbee Creek, Panther Creek , Little Lick Creek , Lick Creek , Surface of Falls Lake , Lake Rogers, Ledge Creek, Holman Creek , Beaverdam Creek, Smith Creek, Robertson Creek , Surface of Falls Lake , New Light Creek , Horse Creek , Upper Barton Creek , Cedar Creek , Surface of Falls Lake Totals: 493, Acres Sq. Mi. 3

8 More than 2,600 miles of interconnected streams and rivers serve as the Upper Neuse River Basin s circulatory system. Adjacent to this network of streams is a large and complex system of riparian corridors that serve as the living filter for the watershed. The watershed s forested riparian buffers help protect the land, filter pollutants and sediment from runoff, regulate stream and air temperatures, control the flow and velocity of stormwater runoff, and provide essential wildlife habitat. The quality and integrity of the stream channels and habitat are directly influenced by the condition of the riparian corridor. Put simply, the system of natural riparian buffers is essential to the long-term health of the surface waters within the Upper Neuse River Basin. Table 2 summarizes the benefits of stream buffers. Additional information about the benefits of riparian buffers is provided in TJCOG s Technical Memo: Riparian Buffer Series, No. 1- An Introduction to Riparian Buffers (a copy of that report is included in appendices). As understanding of the importance of riparian buffers has increased, local, state and federal governments, conservation organizations, and private property owners have expanded efforts to protect and restore riparian buffers in the watershed. Those efforts have included acquisition of greenways and important natural areas, adoption of more stringent riparian buffer protection requirements, and development of education and awareness and landowner outreach programs. To date, approximately 60,040 acres of land (about 12.2%) in the watershed is protected open space. Despite those efforts, additional population and economic growth and land development is putting greater pressure on the Upper Neuse River Basin s riparian corridors, and subsequently the watershed s water resources and aquatic and terrestrial habitat. In the Neuse River Basinwide Water Quality Plan (North Carolina Division of Water Quality; December, 1998), the State reports that of the 562 stream miles evaluated in the watershed, 19.2 miles (3.4%) are not supporting their intended uses. Another 37.6 miles (6.7%) are only partially supporting their uses (see Figure 2). During the period from 1993 to 1998, the combined total miles of non-supporting and partially supporting streams in the watershed increased by nearly 42% (from 40.3 to 56.8 miles). In response to these problems, the State of North Carolina has developed a number of water quality management strategies for the study area, including mandatory requirements for the establishment of 50-foot wide riparian buffers. In addition, the North Carolina Wetlands Restoration Program report titled Basinwide Wetlands and Riparian Restoration Plan for the Neuse River Basin (1998) has identified the Upper Neuse River Basin as a priority area for wetland and buffer restoration and protection efforts and wetlands restoration funding. To protect and restore water quality, riparian buffer protection and restoration efforts must continue and be strengthened where possible. The Upper Neuse River Basin Riparian Buffer Study project was undertaken to assist interested parties in these efforts. 4

9 Table 2. Twenty Benefits of Urban Stream Buffers Reduces watershed imperviousness by 5%. An average buffer width of 100 feet protects up to 5% of watershed area from future development Distances areas of impervious cover from the stream. More room is made available for placement of BMPs, and septic system impacts can be reduced. (f) Reduces small drainage problems. Propoerties located too close to a stream may experience flooding, standing water, and bank erosion. Buffers can greatly reduce complaints. Stream right-of-way allows for lateral movement. Most stream channels shift or widen over time. A buffer protects both the stream and nearby properties. Effective flood control. Other expensive flood controls are not necessary if the buffer includes the 100-year floodplain. Protection from streambank erosion. Tree roots consolidate the soils of floodplains and stream banks, reducing the potential for severe bank erosion. (f) Increases property values. Homebuyers perceive buffers as attractive amenities. 90% of buffer administrators believe buffers have a neutral or positive impact on property values. (f) Increased pollutant removal. Buffers can provide effective pollutant removal for development located within 150 feet of the buffer boundary, when properly designed. (f) Foundation for present or future greenways. The linear nature of riparian buffers provides for connected open spaces. (f) Provides food and habitat for wildlife. Leaf litter is the base food source for many stream ecosystems. Forests also provide woody debris that creates cover and habitat structure. (f) Mitigates stream warmings. Shading by forest canopy prevents further stream warming in urban watersheds. (f) Protection of associated wetlands. A wide stream buffer can include riverine and palustrine wetlands that are frequently found along the stream corridor. Reduces disturbance to steep slopes. Removing construction activity from these sensitive areas is the best way to prevent severe rates of erosion. (f) Preserves important terrestrial habitat. Riparian corridors are important transition zones, rich in species. A mile of stream buffer can provide 25 to 40 acres of habitat area. (f) Corridors for conservation. Unbroken stream buffers provide highways for migration of plant and animal Populations. (f) Essential habitat for amphibians. Amphibians require both aquatic and terrestrial habitats and are dependent on riparian environments to complete their life cycle. (f) Fewer barriers to fish migration. Migrating fish populations are enhanced when stream crossings are prevented or carefully planned and constructed. Discourages excessive storm drain enclosures and channel hardening projects. Buffers can reduce the extent to which headwater streams are extensively modified. Provides space for stormwater ponds and BMPs. When properly placed, structural BMPs within the buffer can be an ideal location for BMPs that remove urban pollutants and control the flow of runoff. Allowance for future restoration. Even a modest buffer can provide space and access for future stream restoration, bank stabilization, or reforestation. (f) indicates benefit amplified by, or requires, forest cover within some or all of the buffer. Modified from Scheuler, Center for Watershed Protection, Watershed Protection Techniques. Vol. 1, No. 4:

10 Figure 2. Upper Neuse River Basin: Use Support Ratings for Evaluated Streams Legend Supporting Partially Supporting Non-Supporting N W E S Data Source: NC Division of Water Quality, Triangle J Council of Governments Geographic Information System June, 2000 * All Hydrologic Unit Numbers shown begin with

11 Under this project, a general assessment of riparian buffer conditions has been completed, and an ArcInfo/ArcView Geographic Information Systems (GIS) based riparian buffer prioritization model has been developed for the watershed. In addition, a property parcel level Riparian Buffer Protection Information Management System has been established to maintain information relative to riparian area protection efforts in the watershed. The reviewer should recognize that this preliminary review is intended to serve as a planning level guide to identify potential target areas for riparian area protection and restoration/ reforestation. Field inspection of potential protection and restoration sites must be conducted prior to more detailed planning and funding of proposed protection and restoration activities. Landowner willingness and cost considerations have not been included in this analysis. The Extent and General Character of Riparian Corridors in the Upper Neuse River Basin To support the riparian buffer protection and restoration planning effort, an initial estimate of perennial and intermittent streams has been developed and a general assessment of current riparian area conditions has been completed. For the purpose of this study, a digital coverage of the perennial and intermittent streams shown on U.S. Geological Survey 1:24,000 topographic maps has been used as the initial basis for designating riparian corridors in the Upper Neuse River Basin. From this information, it is estimated that the Upper Neuse River Basin water resource circulatory system is comprised of at least 2,600 miles of perennial and intermittent streams. Table 3 shows the estimated number of stream miles by 14-digit hydrologic unit within the Upper Neuse River Basin (excluding the three hydrologic units that make up the surface area of Falls Lake). Of those streams, 562 stream miles, or 22%, were evaluated and assigned use support ratings by NCDWQ during the Neuse River basinwide planning process. The 1:24,000 scale stream coverage is the most detailed digital coverage of streams that is currently available. However, based on field investigations by the North Carolina Division of Water Quality this coverage is considered to under-represent the actual extent of perennial and intermittent streams and associated riparian corridors in the Upper Neuse River Basin. This analysis will be updated if and when improved and readily accessible information about the extent and location of stream reaches in the Upper Neuse River Basin becomes available. To support this project, the U.S. Environmental Protection Agency s Landscape Characterization Spatial Analysis Laboratory (USEPA/LCSAL), located in Research Triangle Park, North Carolina, provided TJCOG a digital coverage of Neuse River Basin Land Use/Land Cover (NRB LULC). That coverage was completed by USEPA/LCSAL in April 2000 and was based on an intensive analysis of satellite imagery and aerial photography from 1998 and It has a resolution of 15-meters, and there are 50 land cover classes. This coverage is much more current, more detailed in land cover classes, and finer in resolution than the land cover coverage available through the North Carolina Center for Geographic Information and Analysis. 7

12 Table 3. THE UPPER NEUSE RIVER BASIN: LAND AREA, PRIMARY SURFACE WATERS, AND ESTIMATED STREAM MILES, BY 14-DIGIT HYDROLOGIC UNITS 14-Digit Hydrologic Land Area Estimated Unit Code Acres Sq. Mi. Primary Surface Waters Stream Miles , North Flat River, Chappels Creek , South Flat River, Alderidge Creek, Bushy Fork 186 Creek , Flat River , Deep Creek, Rock Fork Branch , Lake Michie, Flat River, Dry Creek, Dial Creek , North Fork Little River, Buffalo Creek , South Fork Little River, Forrest Creek , South Fork Little River , Little River Reservoir, Little River , Lake Orange, West Fork Eno River, East Fork Eno 94 River , McGowans Creek, Sevenmile Creek, Lake Ben 123 Johnson , Eno River, Strouds Creek, Stoney Creek , Eno River, Crooked Creek , Eno River , Lake Butner (Holt), Knap of Reeds Creek, Camp 106 Creek Knap of Reeds Creek , Ellerbee Creek, Panther Creek , Little Lick Creek , Lick Creek , Lake Rogers, Ledge Creek, Holman Creek , Beaverdam Creek, Smith Creek, Robertson Creek , New Light Creek , Horse Creek , Upper Barton Creek , Cedar Creek 44 8

13 Using the NRB LULC and following a protocol developed by the Virginia Institute of Marine Science in the College of William and Mary (Hershner et. al., Riparian Forest Buffer Targeting for the Rappahannock River Watershed, 1997), each of the 14-digit hydrologic units in the study area was evaluated using two indicators: (a) the proportion of the hydrologic unit s land use/land cover that has an increased potential to contribute to nonpoint source pollution and (b) the proportion of each hydrologic unit s total land use/land cover within the 330-foot riparian corridor that has an increased potential to contribute to nonpoint source pollution. For this analysis, land uses/land covers classified as developed and agricultural are considered to be potentially polluting land use/land cover. Each hydrologic unit s value for these two indicators was determined (see Figure 3 for sample graph of results). The highest one-third of the hydrologic unit values were ranked high for the indicator. Figure 4 maps the results of the evaluation of these two indicators. Considering the results of both the hydrologic unit-wide and the riparian corridor-wide analyses, it is apparent that most of the hydrologic units within Durham, Orange and Person counties and the Butner area have the highest relative NPS potential. Figure 3. Upper Neuse River Basin: Estimated Total Area of Potentially Polluting Land Uses as a % of Total Area, By 14-Digit Hydrologic Unit (Based on USEPA's 1998 Land Use/Land Cover Coverage) Potential Polluting Area as % of Total 70.00% 60.00% 50.00% 40.00% 30.00% 20.00% 10.00% 0.00% ` HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU

14 Figure 4. Upper Neuse River Basin: NPS Potential Relative Nonpoint Pollution Potential by Hydrologic Unit Relative Riparian Area Nonpoint Pollution Potential by Hydrologic Unit Legend High Medium N Low W E S * All Hydrologic Unit Numbers shown begin with Triangle J Council of Governments Geographic Information System June, 2000

15 As a final step in assessing riparian corridor conditions, the NRB LULC was used to identify non-forested areas within 330 feet of surface waters. Figure A-6 (in the map folder at the end of the report) shows the extent of non-forested areas within the 330-foot riparian corridor. To generally assess each hydrologic unit s relative potential for reforestation, the amount of agricultural, non-urban herbaceous, and barren cover within the 330-foot riparian corridor as a percent of the total land area within the corridor was determined. Hydrologic units were then ranked according to four levels of reforestation potential. Figure 5 shows the results of that ranking. Finally, using the NRB LULC, TJCOG staff developed an estimate of the percent imperviousness of each 14-digit hydrologic unit in the study area. Figure 6 summarizes the results of that analysis, and identifies those hydrologic units in which non-supporting or partially-supporting surface waters are located (as determined by NCDWQ). As expected, the two hydrologic units that clearly have the greatest percent imperviousness (more than 21% and 15% imperviousness, respectively) have the lowest-rated streams in the Upper Neuse River Basin. Evaluation of Existing Local and State Riparian Buffer Requirements TJCOG has conducted an analysis of local government requirements applicable to the establishment and protection of riparian buffers within the Upper Neuse River Basin. The results of this analysis are summarized in TJCOG Technical Memo: Riparian Buffer Series, No. 4- Local Ordinances For Protecting Riparian Buffers. A copy of that report is included in the appendices to this report. Some of the key findings of this analysis are: some local governments within the Upper Neuse River Basin have implemented some of the most protective riparian buffer requirements in the State. Of particular note, Durham and Orange Counties require some buffers as wide as 150 feet, and a couple of jurisdictions require setbacks from the buffer; several local governments recognize that perennial and intermittent streams shown on USGS maps and other maps are not based on any standard scientific methodology, and do not provide a sound basis for determining what riparian areas should be subject to regulation and to what degree should those areas be protected. Some local governments require buffers along any point that drains a watershed of a specified size. the State s Neuse River Basin riparian buffer protection requirements now mandate protection of a 50-foot buffer adjacent to both sides of surface waters. Prior to that requirement, several local governments in the Upper Neuse River Basin did not require any buffers along intermittent streams; and local government riparian buffer protection programs do not include any significant education or monitoring components. 11

16 Figure 5. Upper Neuse River Basin: Relative Potential for Reforestation of 330-Foot Riparian Corridor, by Hydrologic Unit (not considering economic feasibility or landowner interest) Potential 330-Ft. Zone Reforestable Area Highest ( >18% ) Moderate - High ( 10% - 18% ) Low - Moderate ( 5% - 10% ) N Lowest ( <5% ) W E S Triangle J Council of Governments Geographic Information System June, 2000 * All Hydrologic Unit Numbers shown begin with

17 Figure 6. Upper Neuse River Basin: Estimated % Imperviousness, By 14-Digit Hydrologic Unit (Based on USEPA's 1998 Land Use/Land Cover Coverage) 25.00% Estimated % Imperviousness 20.00% 15.00% 10.00% 5.00% 0.00% HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU HU Red- Indicates Non-Supporting Stream in HU Pink- Indicates Partially-Supporting Stream in HU 13

18 Riparian Buffer Protection Goals The following initial riparian buffer goals are recommended for consideration by the UNRBA. These goals will be considered for inclusion in the Upper Neuse Watershed Management Plan which is currently under development. That Plan is anticipated to be formally considered and adopted by the UNRBA s member governments. Goal #1: (Long-term) Assure that streams and reservoirs in the watershed are protected by a riparian forest or other appropriate buffer. Goal #2: Conserve existing forests along streams and reservoir shorelines. Goal #3: Increase watershed-wide riparian forest buffers through restoration and reforestation of the riparian area, with priority being given to those areas that will provide the greatest benefit. Goal #4: Convert a minimum of 30% of non-forested, non-urban land uses within the riparian corridor to forest cover (complements basinwide nitrogen reduction effort). Goal #5: Demonstrate the ability of bioengineering techniques to serve as a durable and environmentally acceptable system for long-term stabilization of eroding streambanks. Goal #6: Provide education and landowner outreach programs explaining the benefits of riparian forest buffers and other stream protection measures. Priority Areas For Riparian Buffer Protection and Restoration With the assistance of the Upper Neuse River Basin Riparian Buffer Study Committee, a GISbased computer model was developed to help determine priority areas for riparian buffer protection and restoration within the watershed. Prior to the development of the model, riparian buffer modeling efforts in five other parts of the country were studied and summarized in TJCOG Technical Memo: Riparian Buffer Series, No. 2- A Summary of Selected Riparian Buffer Models (a copy of that report is included in the appendices). Following the determination of the attribute information that could be readily incorporated into a GIS-based model, a doable riparian buffer model was developed by the Study Committee and TJCOG staff. The modeling approach is generally described in TJCOG Technical Memo: Riparian Buffer Series, No. 3- Prioritizing Riparian Buffers for Protection and Restoration (a copy of that report is included in the appendices). The model includes a prioritization matrix that is organized around the four major goals selected for the buffer protection and restoration program: Water Quality; Ecosystem Integrity; Recreational and Educational Use; and Ability to Prevent Loss of Life, Injury, and Property Damage. The Study Committee, which was comprised of individuals representing a 14

19 wide variety of perspectives and agencies, ranked the goals according to their level of importance. The weight assigned to each goal is as follows: Goal Weight Water Quality 39% Ecosystem Integrity 27% Recreational and Educational Use 15% Ability to Prevent Loss of Life, Injury, and Property Damage 19% The Committee also assigned points to thirteen different attributes based on the relative importance in advancing a given goal. The attributes and their respective weight within each goal are shown in the Table 4. Table 4. Summary Listing of Attributes Used in Prioritization Model, And Respective Weights of Attributes By Major Goal Weight Within Goal Current Attributes Relating to Water Quality Goal Estimated erosion rate/potential.37 Non-forested riparian corridor within 100 feet of surface water.33 Relative water supply watershed importance (critical vs. protected).30 Current Attributes Relating to Ecosystem Integrity Goal Adjacency to land already protected through ownership.17 Extent to which site is part of interconnected forest land.22 Presence of wetlands.18 Presence of significant natural areas.24 Presence of significant aquatic species.19 Current Attributes Relating to Recreational and Educational Use Goal Proximity to schools and parks.39 Proximity to Class B waters.38 Proximity to nationally or locally significant cultural resources.23 Current Attributes Relating to Loss of Life, Injury and Property Damage Goal Site is within FEMA-delineated floodplain 1.00 Using GIS, for each unit of analysis (15-meter pixel size) the total points applicable to each goal were determined, compared and then ranked into four priority categories. The results were then graphically displayed for each of the four major goals, and then combined into a composite analysis of the relative rank of a given pixel considering all four major goals. Figures A-1 through A-4 (in the map folders at the end of the report) are watershed maps that show the results of the Upper Neuse River Basin riparian buffer prioritization modeling effort, based on the relative weighting that has been assigned to each of the four major goals and the associated attribute information. Figure A-5 shows the results of the composite analysis, where all four goals are considered together. 15

20 Based on this initial watershed-scale analysis, the highest priority hydrologic units for riparian protection appear to be (last 5 digits of the 14-digit hydrologic units are shown): HU 10050; HU 20040; HU 30020; HU 50020; HU and HU The highest priority hydrologic units for riparian corridor reforestation/restoration appear to be (last 5 digits of the 14-digit hydrologic unit number are shown): HU 10010; HU 10020; HU 10030; HU 10040; HU 20010; HU 20020; and HU The Upper Neuse River Basin Riparian Buffer Protection Model summarized here is only a starting point- it can be updated, enhanced and improved as additional information and more detailed coverages become available. Need For Buffer and Streambank Improvements Plan for the Upper Neuse River Basin It was envisioned that one product of the Upper Neuse River Basin Riparian Buffer Study project would be a multi-year Riparian Buffer and Streambank Improvements Plan for the Upper Neuse River Basin. However, after discussing this concept with local government staff, it is apparent that such a plan must be general in nature due to the difficulty of planning, designing, funding and actually implementing riparian buffer protection and restoration projects. Local governments, the Clean Water Management Trust Fund, the Natural Resources Conservation Service, and others have experienced significant challenges and delays in undertaking such projects. As an alternative approach, a summary of planned local government open space and greenway projects and proposed funding levels within the Upper Neuse River Basin has been compiled and summarized on Table 5. Based on that information, local governments in the Upper Neuse River Basin plan to invest more than $9.15 million in identified open space and greenway projects within the Upper Neuse River Basin. This reflects local governments considerable commitment to open space protection within the watershed. This table will periodically be expanded and updated to reflect current information regarding planned open space and greenway projects in the watershed. Riparian Buffer and Streambank Protection Information Management System As part of this project, TJCOG has established a Riparian Buffer and Streambank Protection Information Management System to assist parties involved in riparian buffer protection and restoration efforts, and to aid in measuring progress and program accomplishments. The foundation for this system is a GIS coverage of property parcels within the study area. With the assistance of the local governments within the Upper Neuse River Basin, TJCOG has compiled a detailed GIS coverage of property parcels for nearly all of the study area (the parcel-level coverage for Person County is currently under development and is anticipated to be completed by the end of 2000). This coverage provides land ownership, tax value of the land and improvements, parcel size, zoning, and related information for each land parcel. 16

21 Creedmoor Table 5. UPPER NEUSE RIVER BASIN: EXPECTED LOCAL GOVERNMENT FUNDING FOR RIPARIAN BUFFER PROTECTION AND RESTORATION EFFORTS AND GREENWAY DEVELOPMENT WITHIN THE UPPER NEUSE RIVER BASIN FY 2001 FY 2002 FY 2003 FY 2004 FY 2005 TOTAL City of Durham Watershed Land Acquisition $1,000,000 $500,000 $600,000 $800,000 $500,000 $3,400,000 Open Space and Greenways $0 South Ellerbe Creek Natural Area $300,000 $300,000 American Tobacco Trail (Neuse) $375,000 $375,000 Little Lick Creek Corridor (3.6 of 11 mi) $808,000 $808,000 Other Trails in Neuse Basin $1,202,000 $1,202,000 Durham County $260,000 $180,000 $240,000 $240,000 $240,000 $1,160,000 Open Space and Greenways Little River Park (Non-CWMTF $) Draft Parks and Recreation Plan now under review. Franklin County Granville County Hillsborough Orange County $120,000 $240,000 $300,000 $300,000 $300,000 $1,260,000 Lands Legacy Program Open Space and Greenways Little River Park (Non-CWMTF $) Person County Raleigh Honeycutt and Macon Rd. Creek Greenways $646,000 $646,000 Roxboro Stem Wake County Wake Forest Open Space Plan now under development. Proposing to develop an Open Space Plan in near-term. TOTALS: $2,701,000 $2,930,000 $1,140,000 $1,340,000 $1,040,000 $9,151,000 Wake County currently has an Open Space Plan under development. Proposed projects and funding levels will be identified in the final plan. A draft Parks and Recreation Plan for Durham County is under review. Proposed projects and funding levels will be identified in the final plan. Orange and Durham counties natural area acquisition programs have been recently established and most proposed projects have not yet been identifed. Orange and Durham funding levels are based on assumption that 60% of program expenditures will be for projects in the Neuse River Basin. Actual timing of expenditures may vary considerably depending on acquisition progress. 17

22 In cooperation with the UNRBA s member governments, this property parcel coverage will periodically be updated to reflect changes in land ownership type (public, private, non-profit, etc.). Figures 7 through 11 illustrate one way the parcel level coverage can be used to support these efforts. Following the GIS analysis of land use/land cover, significant non-forested riparian areas were identified and then overlayed with the property parcel coverage to identify potential reforestation/restoration sites. The product is a planning-level map that can be used to verify actual conditions. Where potential protection and restoration sites are identified and field verified, property and landowner contact information can then be readily accessed from the property parcel coverage. Property parcel information can be tabulated and summarized by area, such as by 14-digit hydrologic units. As riparian buffer protection and restoration projects are implemented, information regarding the date, type and cost of acquisition/restoration and the responsible party (or parties) can be entered into the system for future reference, mapping and analysis. As shown on Figure 12, actual site photographs can be hot-linked to the information system. The parcel coverage summarized above is also being used to support the Upper Neuse watershed management planning project now underway. The parcel level coverage that includes current and future zoning attributes provides information needed to estimate current and potential pollutant loads in the watershed. Watershed loading and water quality response models are being developed to assess the impacts of current and future development in the Upper Neuse River Basin. The success of the Upper Neuse River Basin Riparian Buffer and Streambank Restoration Information Management System will depend on the extent to which local, state and federal agencies and other organizations are willing to provide the necessary information for the system. TJCOG has requested the support of several agencies and organizations in this effort. Building Partnerships to Promote and Implement Riparian Buffer Protection and Restoration TJCOG is strongly committed to working with other organizations on cost-effective publicprivate partnerships that promote and implement riparian buffer protection and restoration activities in the Upper Neuse River Basin and in other watersheds in the region. A wealth of valuable information and assistance on this topic is already available- the challenge is to make that information readily available to those who need it. To help meet this challenge, TJCOG has developed a reference list of riparian buffer protection and restoration resources for distribution to local agencies and the general public. Additionally, TJCOG will (a) share the results and products of this riparian buffer study project with interested public, non-profit and private organizations and the general public, and (b) assist interested parties in pursuing technical and financial support for riparian buffer protection and restoration projects. 18

23 I-85 Hillandale Golf Course Ellerbe Creek Figures 7A and 7B. Top: GIS map analysis view of Ellerbe Creek Riparian Corridor in the vicinity of Hillandale Golf Course, on the west side of Durham. The areas shaded light brown indicate non-forested areas located within approximately 300 feet of the watercourse. Bottom: Downstream view of a significant stretch of predominantly non-forested riparian corridor along Ellerbe Creek, adjacent to Hole #2. 19

24 US 501 Figure 8A and 8B. Top: GIS analysis view of the US Highway 501 and S. Lowell Road area, north of Durham in Durham County. The areas shaded light brown indicate nonforested areas located within approximately 300 feet of the watercourse. Bottom Left: Looking upstream at a non-forested stream corridor (as seen from S. Lowell Road). 20

25 St. Mary s Rd. Figures 9A, 9B and 9C. Top: GIS map analysis view of St. Mary s Road area, located northeast of Hillsborough in Orange County. The areas shaded light brown indicate nonforested areas located within approximately 300 feet of the watercourse. Bottom Left: Looking downstream along identified stream channel, as seen from St. Mary s Road. The banks of this stream are downcut from erosion. Bottom Right: Looking downstream along an identified non-forested stream corridor running parallel to Schley Road, in Orange County. 21

26 Stem Lake Holt Figures 10A and 10B. Top: GIS map analysis view of Lake Holt and the surrounding watershed, northwest of Butner in Granville County. The areas shaded light brown indicate non-forested areas located within approximately 300 feet of the watercourse. Bottom: View of small algae-covered pond located immediately upstream of Lake Holt, west of Old Rte

27 Figures 11A and 11B. Top: GIS map analysis view of the Lake Rogers Watershed, on the north side of Creedmoor. The areas shaded light brown indicate non-forested areas located within approximately 300 feet of the watercourse. Bottom: Looking downstream along identified non-forested stream channel in the Lake Rogers Watershed. 23

28 Figure 12. ArcView software screen view of parcels, non-forested riparian corridors, and streams, with hot-linked photograph from watershed image file. 24

29 For Additional Information To obtain additional information about the Upper Neuse Riparian Buffer Study Project And the Prioritization Model please contact: To obtain information about the Upper Neuse River Basin Association and the Association s watershed management efforts please contact: Water Resources Project Director Executive Director Triangle J Council of Governments Upper Neuse River Basin Association P.O. Box P.O. Box Research Triangle Park, NC Research Triangle Park, NC Tel: (919) Tel: (919) Fax: (919) Fax: (919) Avid canoeists running rapids on the Eno River, near Few s Ford. The water resources of the Upper Neuse River Basin provide a wide range of valuable environmental, recreational, and economic benefits. Efforts to protect and restore the watershed s system of riparian corridors will help to ensure that future generations may enjoy the same benefits that the current generation enjoys from these resources. 25