AGENDA # 4c
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TO: |
Roger L. Stancil, Town Manager |
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FROM: |
George Small, P.E., Director of Engineering Sue Burke, P.E., Stormwater Management Engineer Trish D’Arconte, Stormwater Engineering Technician |
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SUBJECT: |
A Resolution Authorizing the Town Manager to Act as the Town’s Agent for an EPA 319 Grant Fund Application and Associated Project Documents in Support of the Bolin Creek Watershed Restoration Initiative |
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DATE: |
January 28, 2008 |
This report provides information about, and requests the Council’s support for, participation in a grant application under the US Environmental Protection Agency’s 319 grant program for the Bolin Creek Watershed Restoration Initiative. The Town of Chapel Hill would be the lead agency on the grant application and the Town of Carrboro would be a participating agency. The attached resolution would: 1) authorize the Town Manager to act as the Town’s agent in all matters pertaining to the Town’s EPA 319 grant application and any subsequent grant award documents; 2) authorize the Town to provide a local match for 319 grant funds applied to Town projects over the course of three years and; 3) authorize the Town Manager to sign a Memorandum of Agreement for cost-sharing with the Town of Carrboro and describing the obligations and responsibilities of each jurisdiction if grants are awarded.
The Town’s share would be funded by the Stormwater Management Utility Fund. Funds are available in the current budget year and have been included in the Stormwater CIP budget for future years.
Large segments of Bolin Creek have been rated by the NC Division of Water Quality (NC- DWQ) as impaired based on a fair/poor benthic macroinvertebrate community. According to a 2003 assessment of the Little Creek watershed, sediment, habitat degradation, and toxic substances are the main causes of this impairment.
As part of the US Environmental Protection Agency’s Watershed Restoration Program, staff from the Towns of Carrboro and Chapel Hill, and from NC-DWQ came together to create the Bolin Creek Watershed Restoration Initiative. The main goal of this multi-year effort is to have the stream removed from the 303(d) List of Impaired waters by improving water quality and physical conditions in Bolin Creek, and restoring biological health and a more natural hydrology to the Bolin Creek watershed as a whole.
EPA’s 319 Grant Program provides assistance to communities to address impaired waters and nonpoint sources of pollution by developing or implementing a Watershed Restoration Plan. Grant funds are used to implement projects that will have defined, measurable results in improving watershed conditions. Since 2006, the two Towns have been working with EPA to select projects that would be appropriate for 319 grant funds and help meet the overall watershed restoration goals. However, available reports and recommendations for the watershed provided few sufficiently detailed recommendations for projects to restore any of the watersheds, none of which were directly targeted at identified problems.
Using the Clean Water Management Trust Fund mini-grant funds approved in November 2006, the two Towns contracted with Earth Tech to conduct a geomorphic assessment by walking all perennial and intermittent streams in the Bolin watershed, as well as most ephemeral streams. They looked for and described areas of geomorphic instability such as erosion, deposition, channel incision or alteration, of which they catalogued at least 100 sites. They looked for evident sources of problems such as problems with outfalls, land use, riparian cover, etc., and prescribed methods to alleviate or correct the problems for approximately 50 sites.
A final list of conceptual project designs for 32 sites was highlighted in a Project Atlas. Projects were prioritized based on construction cost, cost per ton of sediment removed, project visibility, construction access, and how likely it was that the problem would worsen. These projects were further reviewed by Carrboro and Chapel Hill staff and screened for a set of projects for implementation using various factors including a subwatershed focus for greatest effect, visibility to the public, feasibility or reliability of BMP proposed, landowner issues, regulatory floodplains, and proximity to utility lines or other infrastructure.
Features of the proposed set of projects recommended by the Town staffs include:
Town staff is proposing to submit a 319 grant application, due February 11, 2008, in cooperation with the Town of Carrboro and the NC State University’s Water Quality Group to implement the five projects described below (Please see Attachment 1 for the project locations).
Town staff made a presentation to the Stormwater Advisory Board about the Bolin Creek 319 grant application at its December 2007 meeting. The Board unanimously endorsed the proposed project list and is in full support of the grant application. It is anticipated that the Stormwater Advisory Board will be an active participant in the development of the Watershed Restoration Plan.
A small stream traversing Carrboro’s Baldwin Park, flowing into Tanyard Branch, was highlighted as one of the 32 high priority projects in the Earth Tech report. This stream was estimated by Earth Tech to contribute 28.3 tons of sediment per year due to scour and erosion. Direct runoff from streets and minimal vegetation on the banks creates very poor instream habitats for macroinvertebrates and fish.
A tributary to the Baldwin Park stream flows along the Carrboro-Chapel Hill border and has similar problems. This was not identified as high priority for Chapel Hill because there are projects where there are much greater erosion problems. However, the restoration team’s requirement for measurable results can be more readily obtained by a subwatershed focus that groups projects together to maximize effect. Therefore, the tributary to the Baldwin Park stream has been recommended and included in the project.
The conceptual project plan includes stream restoration along approximately 300 feet of each tributary, enhancement of riparian vegetation on 400 additional feet of stream, and installation of three stormwater structures to reduce the effects of direct, high-energy runoff from area streets that can degrade restored channels.
A tributary to Mill Race had one of two gullies highlighted as one of the 32 high priority projects in the Earth Tech report. This gully was estimated by Earth Tech to contribute 701 tons of sediment per year. A second nearby gully is similarly steep but has not cut into the hillside as deeply.
The receiving stream is suffering from a variety of sediment impacts along its length, from erosion undermining an OWASA pipe crossing to deposition of sand-pea gravel sidewalk material from North Street in the stream. Banks are eroding along the length of the stream due to stormwater inputs, clearing of vegetation for a sanitary sewer line, and the use of very loose material in some areas to create a vehicle-accessible easement in this very rugged valley. These impacts cover and fill in macroinvertebrate and fish habitats in some areas and expose sanitary sewer lines to direct and potentially damaging streamflow in others.
The conceptual project plan calls for repair of the two gullies, non-erosive conveyance of stormwater down the valley sides, methods to address the combination of eroding banks and deposition of sidewalk material in the upper reaches, and, in cooperation with OWASA, address the undermining of the sanitary sewer crossing and erosion along the sewer easement.
Both the Baldwin Park streams and the tributary to Mill Race must be monitored to evaluate effectiveness and demonstrate measurable results. This would include monthly base flow and storm flow water quality samples, methods to monitor streambed and bank erosion, annual cross-section and longitudinal surveys, and measures of vegetation survivorship and benthic habitats.
The development of a nine-element Watershed Restoration Plan is required by the EPA for continued assistance in watershed restoration. The Bolin Creek Watershed Restoration Plan will be focused on the stressors identified in previous watershed studies, and combine these existing watershed studies into a unified plan with the participation of stakeholder groups. This plan will catalogue the many stream and stormwater-related activities in the Bolin Creek watershed, including Town Plans that may affect water resources. Because of these existing resources, the funds requested for plan development are based on the lower end of costs that other watershed groups have borne for plan development.
To demonstrate the measurable results required by the US EPA, some amount of basin monitoring or assessment must be conducted. Concurrent with the development of the Watershed Restoration Plan will be development of a comprehensive monitoring plan (itself one of the nine elements) to measure improvements in the Bolin Creek watershed. This will include a Quality Assurance Program Plan in order to meet requirements for data quality.
Because Bolin Creek was rated as impaired based on macroinvertebrate samples, the Team is planning to conduct biomonitoring at previous NC-DWQ sites across the watershed. Because one of the goals of the Initiative is to restore a more natural hydrology to the watershed, basin monitoring will also include some near-continuous measurement of stream discharge in the lower end of Bolin Creek.
One of the high-priority projects identified by Earth Tech was the bank reshaping and stabilization of an upper segment of Tanyard Branch. By Earth Tech’s estimates this deeply incised and severely eroding stream segment contributes over 1900 tons of sediment per year to Bolin Creek. However, Town staff is aware of significant erosion occurring further upstream of this site just below a large stormwater outfall. The area draining to this outfall is approximately 98% impervious surface (downtown Chapel Hill), and includes a historically-known spring that has been piped. Staff concluded that the energy from this drainage could be sufficient to severely degrade any stream restoration or bank stabilization undertaken downstream.
One possible solution to the most upstream segment is to construct an in-line stormwater management structure to control the flow and volume from the storm drain system. Before this approach can be considered and approved by the state and federal permitting agencies, an alternatives analysis is required. The alternatives analysis compares the costs and effectiveness of using in-line stormwater structures to other methods of controlling stormwater runoff in high-density urban situations such as cisterns, green roofs, underground storage, etc. This analysis also reviews issues related to general public support, landowner cooperation, compatibility of local ordinances and development plans, and feasibility in general.
While this alternatives analysis project does not result in a restoration project to improve stream conditions, the results of this project are necessary to tackle one of the most challenging restoration problems identified: how to mitigate the effects of very high density urban development. An understanding of the true costs of stormwater management in downtown Chapel Hill, where any solution may be considerably costly or difficult to implement, is essential in order to select the most effective and feasible methods.
EPA grants provide 60% of the requested Section 319 funds in return for a 40% cash or in-kind match from the partnering group(s). Projects are expected to be started and completed in three years. In-kind matches can include staff time, or other non-federally-funded projects taking place in the same watershed. NC State University’s Water Quality Group will be contracting with the Team for engineering services, construction oversight, and data analysis. They will be able to contribute a $45,000 cash match over three years.
The Town of Chapel Hill is acting as the lead agency for submitting the Section 319 grant application in order to meet the February 11, 2008 deadline. While the Town of Chapel Hill would be the official applicant, the Town of Carrboro would also be an active participant by providing staff assistance and data, and by sharing in the cost of the required local match. The obligations and responsibilities of each jurisdiction are detailed in the draft Memorandum of Agreement (Attachment 2). This agreement is patterned after a similar document used by the two towns for a Clean Water Management Trust Fund grant that was awarded in 2006.
The cost share is based on proportion of population; Chapel Hill’s proportion is 74.5% and Carrboro’s proportion is 25.5%. These values will be used to allocate costs of shared projects, which for this grant include development of the Watershed Restoration Plan, long-term watershed monitoring, and the Baldwin Park Stream Restoration. The Tanyard Branch alternatives analysis and erosion control on the tributary to Mill Race are located entirely in Chapel Hill Town Limits with 100% of the costs borne by Chapel Hill. The Town’s share (in accordance with the provisions of the Memorandum of Agreement) would be funded by the Stormwater Management Utility Fund. Funds are available in the current budget year and have been included in the Stormwater CIP budget for future years.
The estimated costs for the various projects are shown below. Because monitoring plans must be reviewed by NC-DWQ, monitoring of both individual project locations and the watershed as a whole are subject to some change.
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Baldwin Park Stream Restoration |
$167,120 |
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Tributary to Mill Race Erosion Control |
$147,120 |
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Development of a Watershed Restoration Plan |
$50,000 |
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Tanyard Branch Alternatives Analysis |
$50,000 |
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Long Term Basin Monitoring |
$10,000 |
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5% contingency |
$21,222 |
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10% administrative costs |
$42,424 |
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TOTAL |
$487,876 |
Estimated grant amounts and cost-shares for the agencies and local governments involved (EPA, NC State University, Chapel Hill, and Carrboro) are indicated below:
TOTAL $487,876
EPA grant at 60% - $292,726 Local Match - $195,150
Local Match = $195,150 - $45,000 cash match from NC State University
= $150,150
Breakdown of $150,150 Local Match by jurisdiction
$69,781 Chapel Hill only projects
$80,369 Chapel Hill/Carrboro shared projects
Breakdown of $80,369 Chapel Hill/Carrboro shared projects cost
$59,875 Chapel Hill (74.5%)
$20,494 Carrboro (25.5%)
$129,656 Estimated Chapel Hill Total Cost, over three-year grant project life (includes cash and in-kind)
We recommend that the Council adopt the attached resolution that would: 1) authorize the Town Manager to act as the Town’s agent in all matters pertaining to the Town’s EPA 319 grant application and any subsequent grant agreements; 2) authorize the Town to provide local matching funds for 319 grant funds applied to Town projects over the course of three years and; 3) authorize the Town Manager to sign a Memorandum of Agreement for cost sharing with Carrboro describing the obligations and responsibilities of each jurisdiction if grants are awarded.
