Appendix C Previous Studies

Transcription

1 Appendix C Previous Studies Overview Valley Creek has been the subject of many studies and watershed assessments over the past four decades, with the scope and breadth of these studies varying significantly through the years. Several watershed assessments completed in the 1970 s and early 1980 s by a Conestoga High School s advanced placement biology class were among the first studies to document the environmental distress occurring within the watershed as outlined in Land Use Model for Predicting the Environmental Impact of Future Urbanization on the Valley Creek Watershed with Recommendations for Communities within the Watershed (1973), Valley Creek Watershed Revisited (1983), and The Impact of the Installation of Sewers on Valley Creek and its Surrounding Watershed (1979). In recent years the Valley Creek has been the subject of several comprehensive studies sponsored by Chester County and other governmental organizations. The scopes of these studies have varied from a regional inventory of the County s water resources to an exhaustive evaluation and compilation of technical data related specifically to the Valley Creek Watershed. Several of these documents were developed as part of the County s planning process to accommodate continued growth within the region while providing for the protection of the County s water resources. In addition to the aforementioned studies the watershed has been and continues to be the subject of numerous research investigations completed by academia, watershed conservation groups and various governmental agencies. Of the various studies completed thus far there are five key water resource documents which provide a benchmark of existing conditions, set forth planning goals for the use and protection of the water resources and identify actions necessary to improve the water resources within the Valley Creek Watershed and Chester County. The purpose of this section is not to summarize the content of each of these studies but to direct the user of this document to other references containing supplementary information related to stormwater management and the Valley Creek Watershed. Each of the five key documents concerning the Valley Creek Watershed is briefly summarized in the subsequent portions of this section. Landscapes2 Landscapes2 is Chester County s comprehensive policy plan, adopted in It has brought together growth management and preservation strategies. It has guided municipalities, developers, preservationists, and many others in setting priorities for where and how our county grows including both how to revitalize our urban Appendix C. Previous Studies C1

2 centers and small towns and how best to protect our natural, rural, and historic heritage. For Landscapes2 the county will champion three major initiatives to balance the county s vision of managing growth and preservation, while maintaining the quality of life and sense of place enjoyed by residents. These initiatives advocate for a better, more sustainable future for Chester County and further promote the principles of Landscapes. Build working partnerships The county will join with municipal governments and stakeholders to develop productive partnerships that champion specific actions to achieve the vision of Landscapes. This initiative will involve the following: Retool the Vision Partnership Program; Provide municipal officials with planning information and resources; and Update the guidance offered through county reviews. Create sustainable communities The county will work with the state, municipal governments, and other partners to build and enhance sustainable communities within designated growth areas to provide options for: Transit and infrastructure improvements; Housing and service opportunities; and Economic development and revitalization. Keep Chester County green The county will advocate for a green future. This initiative will: Promote the protection of natural and cultural resources; Use green technologies and energy conservation measures to reduce the impact on the environment; and Encourage the sustainable use of resources in the county and local municipalities. The Original Landscapes Plan The original Landscapes was adopted in 1996 and, since that time, Chester County has become the fastest growing county in Pennsylvania increasing by nearly 70,000 people in the last ten years. The median home price has doubled between 1996 and 2007 (from $156,250 to $312,500). Over 40,000 new housing units have been proposed for development from 1997 to The original plan has made significant progress in achieving the original vision of preserving and enhancing the unique character of Chester County landscapes by concentrating growth in the most appropriate areas. To date, the plan has helped bring growth C2 Appendix C. Previous Studies

3 and preservation together for Chester County through the following accomplishments: Preserved more open space and productive farmland; Preserved more historic resources; Strengthened our urban centers; Promoted transportation options that reduce traffic congestion; and Assisted municipalities in achieving consistent planning programs for managing growth through the creation of the Vision Partnership Grant program and the Urban Centers Revitalization program. Watersheds Watersheds is the water resource component of Landscapes, Chester County s comprehensive plan, which sets forth planning objectives for future growth within the County. The function of Watersheds is to provide a framework for the integration of water resources and land cover decisions that transcend municipal boundaries and is consistent across Chester County. The document describes the stakeholders associated with water resources and enlists there assistance in identifying water resource issues within the county. Seven goals are identified in the document which the County recognizes as essential elements to achieve the level of water resource management needed within the County. These goals are: 1. Engage and Educate Individuals, Communities and Governments in Watershed Stewardship. 2. Enhance Water-Based Recreational and Cultural Resources. 3. Preserve Natural Resource. 4. Improve Water Quality. 5. Reduce Stormwater Runoff and Flooding. 6. Protect Watershed Water Balances. 7. Integrate Utility and Municipal Planning to Meet Future Water Supply and Wastewater Needs. For each of the goals listed above, this planning document provides an overall objective, strategies to achieve the goals and a rational which underscores the importance of each of the goals. Watersheds further identifies key stakeholders in the federal, state, county, and local governments, as well as the private sectors, and describes specific responsibilities of each of the stakeholders necessary to implement the water resource plan useful throughout the County. Watersheds sets forth four criteria in order to prioritize and rank the water resource needs throughout the County. These include: the need for restoring stream water quality and resources at risk, restoring water quality conditions only, reducing stormwater runoff and flooding, protecting stream resources, and protecting ground water (used for subbasin prioritization only). Of the 21 watersheds within the County, Valley Creek is rated along with several other watercourses as being one of the highest priorities within the County for water quality restoration and stormwater management. Although, the Valley Creek is identified as a high priority, the Plan Appendix C. Previous Studies C3

4 states that other water resource objectives within Chester County should not be ignored in order to address the needs within the Valley Creek. In addition to the aforementioned information this resource provides a listing of priority management needs pertaining to each of the watersheds within the county describing the available water resources, growth, land cover, water availability, water usage, stormwater runoff, water quality and regional priorities. Chester County, Pennsylvania Water Resources Compendium The Chester County, Pennsylvania Water Resources Compendium presents the technical basis for the goals and objectives identified in the planning document, Watersheds, mentioned above. It consists of a compilation of technical data, maps, methodologies, and analyses pertaining to all 21 watersheds located across Chester County. The county-wide compendium contains a voluminous amount of information which provides a synopsis of the water resources within the County and offers a benchmark of the existing conditions of these resources. The County intends for the document to be used as a tool to provide for the proper planning of development within the county. The Compendium consists of four parts: A Technical Report, Subbasin Data, Tools for Municipal Implementation, and Individual Watershed Management Plans. The technical portion of the Compendium describes the relationship between responsible planning and good stewardship while emphasizing the correlation between land cover practices and status of the County s water resources. As part of the benchmarking of existing water resources within the County, the technical portion of the Compendium provides specific data for each watershed pertaining to water budgets, land covers, water supply, wastewater treatment, stormwater management, non-point source pollution, impaired waterways and water quality. The document stresses that county government cannot achieve adequate management of the resources alone but relies on the actions of local municipal governments and stakeholders to achieve its objectives. A method of metrics is set forth in the document in order to measure the effectiveness of the program at achieving the intended water resource management objectives. The document provides water budgets, a list of impaired resources and a biological assessment for all 21 of the County s major watersheds. It further prioritizes restoration projects across the County, and within each of the individual watersheds, in order to provide a systematic approach to solve some of the County s most urgent water resource problems. Valley Creek Watershed Action Plan The Valley Creek Watershed Action Plan is a watershed specific description, assessment results and management priorities for the Valley Creek Watershed. Whereas the Chester County, Pennsylvania Water Resources Compendium contains data related to all the major watersheds in the County, the Watershed Action Plan consists only of data and information associated with the Valley Creek Watershed. The majority of the data included in the Watershed Action Plan comes directly from the Chester County, Pennsylvania Water Resource Compendium and is placed in a format that is succinct, making the significance of the data to the Valley Creek Watershed clearly apparent. C4 Appendix C. Previous Studies

5 A large portion of the Watershed Action Plan includes watershed specific data on population trends, land cover, impervious cover, geology, water budget, groundwater supply, water quality, natural diversity and biologic assessment of the Valley Creek Watershed. In addition to the aforementioned data, the Plan includes many tables and numerous maps with information related specifically to the water resources of the Valley Creek Watershed. Most importantly, the Plan evaluates the resource needs within the watershed and lists a series of management objectives and actions to address the needs. The Watershed Action Plan ranked Valley Creek Watershed as high priority in three out of the four areas used to evaluate the needs of water resources throughout Chester County. Management objectives listed in the Watershed Action Plan for the Valley Creek include implementation of municipal stormwater management ordinance, development of an Act 167 plan, execution of NPDES Phase II requirements, implementation of Valley Creek Restoration Plan, implementation of residential pollutant runoff program and provision of ground water balance information to municipalities. In addition to the aforementioned data, the Plan includes a cost analysis or estimate of necessary funding to act upon the management objectives listed in the Watershed Action Plan. Valley Creek Watershed Technical Compendium The Valley Creek Watershed Technical Compendium contains an in depth analysis of the fluvial geomorphology, chemical and biological conditions within the Valley Creek Watershed, providing a benchmark of existing conditions within the watershed. As part of this analysis the Valley Creek Watershed Technical Compendium lists contaminated sites within the watersheds and identifies both the Little Valley Creek and the Valley Creek as having ten stream segments that are presently classified as impaired. Also related to water quality within the watershed, the Compendium cites biologic assessment data from two long term testing sites within the watershed as having assessments indicating the tested stream segments are slightly impacted. The Compendium cites that water quality of the Valley Creek and its tributaries is directly influenced by stormwater runoff from the watershed, with certain land covers and practices within the watershed more responsible than others for contributing nonpoint source pollution to the Valley Creek and its tributaries. The Valley Creek Watershed Technical Compendium analyzed the long term records and testing of 18 chemical concentrations and measurements, in order to assess the water quality within the Little Valley Creek and the Valley Creek. Of the 18 or so water quality parameters analyzed, about half are directly influenced and/or conveyed by stormwater runoff to the Valley Creek s tributaries, impacting the water quality and ecosystems of the water resources within the watershed. Those constituents impacted or conveyed by stormwater runoff to the Valley Creek include: ammonia, chloride, fecal coliform, nitrate/nitrite, ph, phosphorous, sodium, total dissolved solids, total suspended solids and water temperature. The source of this type of pollution within the Valley Creek Watershed can be connected to one of four common land cover practices; effluent from on-lot wastewater treatment facilities (septic systems); contaminants deposited on impervious surfaces; soil erosion; and fertilizer spread on lawns and cultivated areas. With these activities and sources of nonpoint source pollution capable of impacting the tributaries of the Valley Creek directly, any increase in the amount of runoff to Appendix C. Previous Studies C5

6 streams or watercourses effectively transports more additional nonpoint source pollution to these water resources. Therefore, any increase in the amount of impervious surface and loss or reduction of riparian buffer associated with development results in a net increase in the volume and velocity of stormwater runoff flowing to the water resources and ultimately increases the amount of pollution entering the Valley Creek and its tributaries. Although none of the parameters assessed in the Valley Creek Watershed Technical Compendium indicated significant impairment of the water resources, several elements had a clear upward trend toward threshold levels where adverse impacts upon tributaries of the Valley Creek may become apparent. This is the reason a watershed wide integrated stormwater management plan is essential. An integrated stormwater management plan is a valuable tool that is capable, if applied correctly, at slowing and possibly halting the upward trend in the pollution concentrations associated with nonpoint source pollutants in the watershed. This is achieved chiefly by encouraging development within the watershed to mimic the predevelopment water budget of the watershed, thus limiting the post development stormwater runoff velocity or volume from development. Another analytical evaluation included in the Valley Creek Watershed Technical Compendium is a fluvial geomorphology study of the watercourses within the Valley Creek Watershed. This analysis describes the natural processes and precursors responsible for the evolution of the stream into its current configuration and alignment. To accomplish this study, a cruised reach field assessment of the water courses within Valley Creek Watershed was undertaken. Data sheets, including assessment information, photographs, and cross section drawings of various stream segments included in the fluvial geomorphologic study are provided in the appendices to the Valley Creek Compendium. Several recommendations concerning the watershed resulted from the analyses prepared as part of the Compendium. Each of the recommendations is divided into major categories and several minor sub-categories. The recommendations included in the Valley Creek Watershed Technical Compendium and a brief description of each is as follows. Stormwater Runoff Reduction - prepare an Act 167 Integrated Stormwater Management Plan to quantify runoff problems and set forth criteria for improving problem areas. Hydrologic Conditions and Instrumentation - maintain existing stream gages within the watershed and install instrumentation to measure and monitor precipitation and water temperature within the Valley Creek Watershed. Surface Water Quality Monitoring - provide for continued comprehensive monitoring of water quality within the watershed. Biologic Monitoring - continue existing monitoring, complete another synoptic survey within the next five years and develop periodic fish monitoring program. Significantly Contaminated Sites - pursue closure and remedial action related to contaminated sites. C6 Appendix C. Previous Studies

7 Stream Channel Geomorphology - complete specific stream reconstruction projects in problem areas based on the findings from the fluvial geomorphology study. Valley Creek Restoration Plan and Environmental Assessment The Valley Creek Restoration Plan and Environmental Assessment was prepared for the Valley Creek Trustee Council and assesses the value of restoration projects at enhancing the Valley Creek fishery and restoring the natural resources within the watershed. The Valley Creek Trustee Council is composed of representatives of the United States Department of Interior and Commonwealth of Pennsylvania. The U.S. Department of Interior is represented by the Superintendent of Valley Forge National Historical Park and the Commonwealth of PA is represented by the Pennsylvania Fish and Boat Commission (PFBC). The Council was established under the "Superfund" Law when Valley Creek was contaminated in the mid-1980's by polychlorinated biphenyls (PCBs), a well-known carcinogen. PCB contamination was found in fish tissue of fish harvested from the Valley Creek. As the level of the contaminant in the fish exceeded the acceptable level for human consumption as identified by the U.S. Food and Drug Administration, the Valley Creek was redesignated as a catch and release fishery, and stocking of the Creek was halted. This loss of use as well as damages to the natural resources were compensated for by the responsible parties through legal action. The Valley Creek Restoration Plan presents restoration strategies and potential projects that can be implemented to enhance natural resources and improve angler use within the Valley Creek Watershed. This document serves as a primary source of guidance for the Valley Creek Trustee Council in administering Restoration Fund monies. The Plan evaluates two different restoration approaches for the Valley Creek. The first approach is a proactive response to the environmental distress occurring within the watershed and documented in the aforementioned reports and studies. This alternative seeks to implement projects that are directly related to at least one of five major categories to resolve some of the environmental problems occurring within the watershed which relate to the Valley Creek. The five major categories include: Stormwater Management - retrofitting of existing basins to provide water quality features for the treatment of runoff Stream Channel Restoration - stabilization of eroded stream banks and augmentation of the aquatic environment Greenways - protection and expansion of riparian buffers Increased Public Access - expansion of trails and pervious parking areas for anglers to improve access and appreciation of the watershed by the public Fish Restoration - restoration of a fish populations in tributaries to the Valley Creek that once had known fish populations The second alternative investigated in the assessment plan is the no action or a do nothing alternative. This option relies solely on the creek to adapt to the environmental changes occurring in the watershed and requires no special consideration. Appendix C. Previous Studies C7

8 The assessment evaluates the alternatives for their effects upon natural resources, cultural resources and socioeconomics factors within the watershed. As expected, the preferred alternative, is the proactive alternative, undertaking projects in one of the five previously mentioned categories. The assessment indicates the potential benefits to the watershed far outweigh the limited potential negative effects that could occur with the implementation of these types of projects. The report provides a listing of specific projects that could be implemented within the watershed and indicates that preferred projects are those projects that restore injured Trust resources and replace lost biological, ecological, and human services. Evaluation of the Additive Effects of Stormwater Detention Basins at the Watershed Scale The Evaluation of the Additive Effects of Stormwater Detention Basins at the Watershed Scale is a thesis prepared by Clay Emerson, a graduate student at Drexel University, completed a research project in the Valley Creek Watershed during As part of his thesis work Mr. Emerson collected data on approximately 111 existing detention basins in the watershed with the objective of determining the effect of the basins upon the flows in the Valley Creek. Of the 111 basins identified by field work, approximately 26 of the basins contained defects and only approximately 85 basins were evaluated as part of his work in the watershed. In his study, precipitation data was collected and used to complete the stormwater analysis. Emerson determined that instead of reducing the flows the existing basins either had no impact on the majority of the precipitation events that occur in the watershed or in some cases actually caused the peak rate of flow to increase in the watershed. This Act 167 Plan incorporated portions of the Emerson thesis raw data into the development, analysis, and evaluation of the stormwater management criteria for the Valley Creek Act 167 Plan. Other Related Documents In addition to the aforementioned documents, the following additional references were identified by CCWRA as containing information and data related to the Valley Creek Watershed which could be useful for additional studies in the watershed. Although there are numerous other studies that contain information regarding the Valley Creek, the aforementioned studies represent the most relevant and significant documentation of the water resources within Valley Creek Watershed. Chester County - U.S. Geological Survey Stream Conditions of Chester County Biological Monitoring Network, unpublished, Unpublished Summary of Biological Monitoring of Benthic Macroinvertebrates of East Valley Creek Watershed. Keystone Stream Team and Alliance for the Chesapeake Bay, 2003, Guidelines for Natural Stream Channel Design for Pennsylvania Waterways ( Sloto, R.A. and Chester County Water Resources Authority, 1994, Geology, Hydrology, and Ground-Water Quality of Chester County, Pennsylvania. U.S. Geological Survey, 1990, Geohydrology and Simulation of Ground-Water Flow in the Carbonate Rocks of the Valley Creek Basin, Eastern Chester County, Pennsylvania, Water-Resources Investigations Report , 60 p. C8 Appendix C. Previous Studies

9 U.S. Geological Survey, 1998, Effects of Urbanization on Storm-Runoff Volume and Peak Discharge of Valley Creek, Eastern Chester County, Pennsylvania, Water- Resources Investigations Report , 32 p. U.S. Geological Survey, 2000, Physical, Chemical, and Biological Data for Selected Streams in Chester County, Pennsylvania, , Open-File Report , 147 p. U.S. Geological Survey, 2000, Physical, Chemical, and Biological Data for Selected Streams in Chester County, Pennsylvania, , Open-File Report U.S. Geological Survey, 2003, Assessment of Stream Conditions and Trends in Biological and Water-Chemistry Data From Selected Streams in Chester County, Pennsylvania, , Water-Resources Investigations Report , 77 p. Appendix C. Previous Studies C9