This plan was prepared with financial assistance provided by the Commonwealth of Pennsylvania (PA) under a Department of Natural Resources Conservation Rivers Conservation Program Planning Grant and members of the White Clay Watershed Association.

The White Clay Watershed includes all of the lands draining into the White Clay Creek. The watershed encompasses more than 100 square miles in Southern Chester County (PA) and New Castle County (DE).

Actual land cover as of 1990 according to human activities within the watershed are categorized in the map below and summarized in Table 1:

This table indicates that the majority of the watershed is Open Space in the form of agricultural uses and woodlands. A substantial portion of the watershed has also been developed into low density housing. The combined coverage of commercial, industrial, medium and high density residential categories is surpassed by the mushroom facilities. Since 1990, the percentage of agricultural uses has declined as low density residential and commercial development have proceeded. Land use data as of 1995 may soon be available. Consideration of updated data may result in revisions to portions of this plan.

This plan provides a framework for monitoring and improving water quality within the White Clay Watershed. This plan will be a complement to the water quality components of the NW&SS Watershed Management Plan.

Within the Watershed Management Plan, water resources are a major concern both in terms of securing current and future water supplies and environmental protection. Quoting from the Resource Management and Protection Issues section of the draft of the NW&SS:

"Floodplains, wetlands, and riparian areas are the environmentally sensitive home for many of the outstandingly remarkable plant and animal species found within the watershed. The protection of these habitats is critical to the survival of these rare species within the watershed. The protection of these areas will also help to maintain the high level of biodiversity that exists in the watershed."

 And, discussing erosion later in the same section:

"Erosion increasingly threatens the ecological diversity of the White Clay Creek. During storms, sediment pours into and rushes down the creek, temporarily reducing water clarity and settling out to smother the benthic organisms beneficial to the stream. As sediments build up on the stream bed, the creek's water-carrying capacity diminishes, contributing to flooding downstream. Sediment drained into the creek includes erosion from land under construction, urban runoff, agricultural non-point sources and streambank erosion."

Sedimentation is an example of a nonpoint source (NPS) impact on the stream. NPS pollutants come from widely dispersed uses or conditions such as stormwater runoff from streets. Impervious surfaces, which increase stormwater runoff, include roofs, roads, driveways and parking lots. Point sources of pollutants occur at specific sites and are typically a discharge from a pipe or ditch. An example of a permitted point source is a sewage treatment plant (STP).

The WCWA's Stream Watch Program is designed to use aquatic macroinvertebrates to assess water and habitat quality in the WCC. The stream is monitored at the same specific (12) sites at the same time once a year. Samples of the aquatic macroinvertebrates, which consists mainly of insects, are collected then sorted, identified and counted. This quantifies the biodiversity, that is, the number and variety of different families found. In addition, some types are known to be more sensitive to environmental insult than others. It is the presence of the sensitive types, the biodiversity and total numbers of individual types that indicate the health of the stream.

Figure 2, "Average EPT Densities", is the baseline average results for the 12 PA sites of the relative numbers of the more pollution sensitive mayflies, stoneflies, and caddisflies (known collectively as EPT). The relative numbers of these three insect orders are used as general indicators of the stream quality or health. The bars in the graph are plotted in order, starting at the headwaters of each branch of the WCC and working its way downstream toward the DE border. The data plotted in the Figure 2 indicate that there is a decline in the water quality as one proceeds through the sites from the headwaters down into DE. The evidence is in the decline in EPT, with drastic deterioration seen at site 18 (East branch below Avondale) and the poor condition of the sites in the WCC Preserve, 16 (East Branch) and 14 (Main Stem), which are downstream from agricultural, commercial and residential usage. Similar but less dramatic declines are seen on the Middle and West Branches. Site 18 is of great concern because of evidence from the PA Department of Environmental Protection (DEP) reports (in 1986 and 1997) indicating the possible contributions from pesticides and other chemicals from an upstream tributary (Trout Run). Additional results and information on Stream Watch protocol are provided in Appendix A.

This watershed supports a variety of environmental and cultural resources which have important value to the area. The temperate climate and underlying geology throughout the watershed has produced fertile soils which supports a great diversity of plants. The Commonwealth of PA has found three endangered, one threatened and two rare plants species in the PA portion of the WC Watershed. Given these favorable conditions, the landscape also supports a diversity of fish, birds, reptiles, amphibians and other animals. With 44 inches of precipitation annually, the hydrological cycle plays a very important role. Some water runs over the surface, some evaporates, much is transpired by plants, and the rest percolates into groundwater for storage and provides base flow to streams, thereby interfacing with every aspect of the watershed. Thus, water quality in our watershed is the integral backbone of the entire ecosystem.

The NW&SS makes the following observations: "Floodplains, wetlands, and riparian vegetation zones are being adversely affected by land development. Wetlands are being filled, riparian vegetation being cut down and there are encroachments in floodplains throughout the watershed. The cumulative result is an increased loss of biodiversity and a decline in a number of species." (NW&SS) This statement is supported by the WCWA Stream Watch data, as presented here.

Erosion and runoff are a large part of the NPS pollution problem.

Erosion and runoff promoting practices include:

• increase of impervious surfaces due to residential and commercial development
• agricultural activities without the use of Best Management Practices(BMPs)
• inappropriate recreational and earth disturbing activities on steep slopes and streambanks.
• earth disturbances due to commercial and residential construction.

As described in detail in Appendix A, Geographical Information Systems (GIS) provide many different types of landscape information in a coded map format. Of most use to us is the information on land cover (i.e. how people 'use' the land) and how that 'use' is tied to its potential to cause erosion and runoff in the watershed. One may then relate the land cover to stream watch sites so as to better relate how certain land practices may contribute to the degradation of a particular site. In particular, how the land is used can be related to its potential for causing runoff and the accompanying erosion.

The GIS analysis shows high erosion potential in the lower part of the watershed where slopes are steeper and thus land use activities will generate more erosion. Stream Watch data for these sites is indicative of stressed and deteriorated sites. The subwatershed containing site 18, which lies along Routes 1 and 41, has a high percentage of impervious surfaces, creating more runoff, potentially contributing to the low EPT counts seen at site 18. Thus, land cover (or land use) as well as other landscape elements (slope, stream side forests) are features of the landscape which determine the extent of erosion and runoff for that geographical area.

Additional information on the water quality of the East Branch in the vicinity of Avondale is provided by a recent investigation of a 2.5 mile stretch of the East Branch between Avondale and Landenberg by DEP biologists (Boyer, 1997). The macroinvertebrate results agree with WCWA Stream Watch results in this vicinity, while the chemical analysis gives further understanding to the deterioration seen. Of most concern is the potentially toxic concentration of diazinon found in Trout Run ( a tributary immediately upstream from Avondale). Concentrations of this magnitude are indicative of improper usage. In addition, DDT continues to be found although it is no longer in use. Thus, pesticide use from current and past practices may also be contributing to the decline in more sensitive aquatic insects.

With this GIS information, along with the WCWA Stream Watch data, and investigations by the DEP, the prudent landowner may find the basis for improving his/her land practices in order to improve the quality of the surrounding area.

Land Uses potentially contributing to NPS Pollution in the WCC:

• conventional tillage
• mushroom facilities
• high density residential, commercial, and industrial development

There are several contributing factors with multiple layers of influence on the overall decline seen in the watershed. Again, the NW&SS sums up one of the problems as "the inconsistency in the regulations designed to protect these areas among the various municipalities of the watershed...there is a lack of coordination among the federal, state and local governments issuing permits for development projects within these critical habitats." (NW&SS)

Specific water quality improvement issues need to be acknowledged to give impetus to enacting and encouraging BMPs and ordinance changes. The quality of the water and habitat has been degraded for the people and the wildlife of the watershed. The White Clay Preserve, the jewel of the watershed, is receiving water of a quality that is unable to support healthy aquatic populations.

Municipalities, agencies and residents need to join in an action plan to significantly improve the quality of water delivered to the White Clay Preserve. The following suggestions are made:

• Identify and remediate major NPS or point impacts.
• Mitigate the impact of any future development
• Improve the habitat quality for all wildlife and vegetation along the WCC stream corridors

Appendix A discusses some of the practices which are contributing to the decline in the quality of the stream sites along the WCC. The recommendations made can only be effective if the local municipalities act in a concerted effort with each other. As the impact on the stream quality is the result of an accumulation of stressful practices, the improvement must be a consistent effort throughout the WCC watershed.

The following practices and ordinance changes are necessary to begin reversing the degraded water quality in the lower watershed:

• Apply Best Management (Agricultural) Practices, BMP, such as
• cover crop planting
• conservation tillage (such as contour plowing and no till)
• riparian buffers along streams
• manure management
• Improve Ordinances managing sources of runoff:
• limit impervious cover
• drywells for roof drains
• maximize infiltration techniques for stormwater management
• Limit the access to steep slopes along the WCC
• Limit development in floodplains
• Create and maintain riparian buffers along stream

The water quality information developed by the WCWA Stream Watch can only be of practical value if it is made available to municipalities, land planners, engineers and residents.

• The WCWA will provide an annual report of the Stream Watch data. Possible avenues for dissemination of information:
• Contact WCWA for a copy.
• Presentation at public meetings by a representative of the WCWA.
• Mailed to all municipalities as well as Federal, State, and County agencies
• WCWA Web page (http://www.ccil.org/~wcwa)

• The WCWA will coordinate its monitoring activities and facilitate interactions that result from communicating each year's results to:
• PA Fish and Boat Commission (regional office)
• PA Department of Natural Resources (Bureau of Forestry)
• PA Department of Environmental Protection (Volunteer Coordinator)
• PA Department of Agriculture (local agriculture extension representatives)
• Natural Resource Conservation Service (state and local offices)
• US Environmental Protection Agency (Region III office and volunteer coordinator)

The residents of the watershed must support and participate in this plan if it is to succeed. Public input was sought at all stages of development of this plan, but participation in plan implementation is even more critical. All of the following are recommendations for public education and participation in the watershed.

• Public displays and demonstrations at community functions
• Public meeting speakers on watershed issues.

SWRC will continue current programs available to the schools and youth organizations as outlined in Appendix B and in addition will continue to support:

• Envirothon
• Stream School (based on the WCWA/SWRC stream watch protocol)
• Penn London School environmental education activities
• In addition, adoption of the Globe program of student field ecological studies is recommended

• Include watershed activities in community days
• Invite WCWA and SWRC representatives to participate as advisors on ordinance chances and hearings involving water quality issues

Establish informal education and monitoring networks of residents

• Monitor streams in backyards and neighborhood for changes
• Neighborhood education for stream friendly gardening and living