Fish Passage Assessment of Road-Stream Crossings in Cooks Creek Watershed Priority Projects and Conceptual Design Bucks County, Pennsylvania

Transcription

1 November 30, 2012 Bucks County Trout Unlimited c/o Joe Mihok 412 Manor Drive Dublin, PA Scientists, Engineers & Environmental Planners Designing Innovative Solutions for Water, Wetland and Soil Resource Management RE: Fish Passage Assessment of Road-Stream Crossings in Cooks Creek Watershed Dear Joe, We are pleased to provide you with the final product for the fish passage assessment of Cooks Creek. As per the scope we are providing a brief summary that includes a description of each site, site constraints, project opportunities, conceptual design, ballpark cost estimate, and permitting requirements with photos and a conceptual site plan. We intend this document to assist Bucks County Trout Unlimited in seeking grants and building support from the municipality and other potential project partners. Background and Methodology Princeton Hydro utilized publically available geographic data layers to identify approximately 100 potential road-stream crossings utilizing ArcGIS. Building from existing culvert assessment resources (e.g. Vermont Agency of Natural Resources Vermont Stream Geomorphic Assessment, Appendix G: Bridge and Culvert Assessment.), Princeton Hydro developed specialized culvert assessment forms, instructions and field maps for use by volunteers from Bucks County Trout Unlimited and the Cooks Creek Watershed Association, Inc. Princeton Hydro led a hands-on discussion and field training at an existing culvert crossing to train volunteers in the assessment protocol; and, grouped proximal culverts (approximately 3 5) for each team of 2-3 volunteers. Volunteers conducted the culvert assessments throughout the summer and fall of After obtaining the volunteers field data, which included data sheets and photos, Princeton Hydro reviewed the data and began the iterative process of demoting stream crossings that were not barriers to fish passage (e.g. were not perched and had adequate flow depth) or that were of relative low priority for other reasons. Princeton Hydro identified approximately 20 stream crossing retrofit sites and conducted follow-up site visits to confirm volunteers findings, collect additional information, and identify any site constraints. The number of priority crossings was further pared down to eleven (11) crossings through subsequent prioritization based on: 1. public or private ownership of the road; 2. length of stream that would be reconnected; 3. presence of trout; 4. subwatershed size; 5. proximity to the main stem of Cooks Creek; 6. local geology; 7. local land cover; and, 8. past water quality monitoring. PrincetonHydro.com 1108 Old York Road PO Box 720 Ringoes, NJ t f Liberty Place Sicklerville, NJ t f East Uwchlan Avenue Suite 204 Exton, PA t f Main Street Suite 2 South Glastonbury, CT t f

2 Private ownership (i.e. a private driveway) was considered reason for lower priority because private landowners may not be supportive and public grants may be difficult to obtain for work on private property. The length of stream to be reconnected was measured as the distance to the next upstream and downstream barriers. Presence of trout was based on BCTU members local knowledge, volunteer observations and existing sampling records from Pennsylvania Fish and Boat Commission. Crossings with drainage areas that are less than 0.25 mi 2 were deemed lower priority because they are less likely to support trout due to inadequate perennial flow. As one of the implicit goals of the project was to reconnect currently isolated tributaries to Cooks Creek, first barriers off of the main stem were given higher priority than barriers farther removed from the mainstem with one exception: where native brook trout were present. Local drainages underlain by carbonate bedrock yield better water quality and more moderate water temperatures; as such, barriers in those drainages were given higher priority. Similarly, local drainages with greater forest land cover yield better water quality and more moderate water temperatures; barriers in those drainages were given higher priority. Finally, volunteers from BCTU and CCWA who conducted long-term water quality monitoring identified those barriers situated in subwatersheds with relatively higher water quality. All associated materials, including field data sheets, field maps, photos, summary spreadsheet, GIS datalayers, presentation file and other data, are included in a CD accompanying this document. Of the 97 crossings first identified, 11 crossings were identified as potentially appropriate for a retrofit effort. It also became apparent that many potential target crossings were situated consecutively. As such, removing consecutive culverts created an opportunity to maximize the length of stream reconnected. As a basic means of comparison, the length of stream per barrier removed was calculated for each group of consecutive barriers, which helped identify a pair of crossings with the highest priority: sites 19 and 20. A summary sheet and concept designs for these sites follows. Princeton Hydro greatly appreciated the opportunity to work with you on this project. We would like to offer similar services for any other road-stream crossings that BCTU is interested in retrofitting or replacing. If you have comments or questions, please contact us at Thank you. Sincerely, Jacob E. Helminiak, P.E., CFM Senior Hydraulic Engineer Paul M. Woodworth Fluvial Geomorphologist cc: file Princeton Hydro, LLC Page 2 of 6

3 Fish Passage Assessment of Road-Stream Crossings in Cooks Creek Watershed Summary Sheet for Top Priority Projects: Sites 19 and 20 Site 19 Funks Mill Road Site 20 Dogwood Lane Durham Township, Bucks County, PA Durham Township, Bucks County, PA Latitude: Latitude: Longitude: Longitude: Stream Description Sites 19 and 20 are consecutive stream crossings located on an unnamed tributary that joins Cooks Creek approximately 2.8 miles upstream of the Delaware River confluence. Site 19 is on Funks Mill Road approximately 180 feet from the intersection with Dogwood Lane. Site 20 is on Dogwood Land approximately 1,000 feet from the intersection with Funks Mill Road. Through the prioritization process the following information was collected about these two stream crossings: 1. Roads are publically-owned; miles of stream would be reconnected to Cooks Creek main stem; 3. Wild trout is present; 4. Subwatershed size is 0.8 and 0.7 mi 2 ; 5. Site 19 is the first barrier to Cooks Creek; 6. Local geology is dominated by carbonate bedrock; 7. Local land cover is dominated by forest; and, 8. Water quality is favorable. The unnamed tributary is a high-gradient (approximately 6%), step-pool channel approximately 8-10 feet wide and 4 feet deep. The stream also is characterized by cool water temperatures and year-round trout presence. The existing crossings create steep drops that are impassable to trout under most, if not all flow conditions. Site 19 Description The stream crossing at Site 19 creates a barrier to fish passage by shallow flow depths and a nearvertical drop. The 5-foot reinforced concrete pipe constricts flow and bedload transport. The pipe is out of alignment with the stream, as the channel takes a severe right-angle bend to enter the pipe. In addition, erosion is evident on the right bank, where concrete-masonry stabilization has been scoured out of place. Bedload piles up on the upstream side creating a passage barrier. Flow at the head of the culvert is shallow and high velocity. If inadequate road cover exists over the culvert crossing, the height of the road surface may need to be raised, which extends the length of road that would require removal and replacement. In addition, an overhead power-line parallels Funks Mill Road, which will need to be considered during construction. (The overhead high-tension power-lines are not a concern.) Some aspects of the site support a potential retrofit. For example, the downstream invert of the culvert is submerged in a pool under normal flows by a riffle downstream, which indicates that the change in grade from upstream to downstream is not too severe to accommodate with a stream bed constructed of natural materials. Funks Mill Road is not a major traffic artery, making the logistics of temporary road closure less complicated. Finally, it appears that the existing road crossing does not meet current road standards (e.g. road width, guiderails, road cover); in contrast, any replacement of the road crossing will likely be held to such standards. Princeton Hydro, LLC Page 3 of 6

4 Site 20 Description The stream crossing at Site 20 creates a barrier to fish passage by shallow flow depths and a nearvertical drop. The crossing is constructed of a 6-foot reinforced concrete pipe attached to a 9-foot wide concrete box culvert. The concrete pipe restricts flow and bedload transport, creating a sediment blockage at the culvert inlet. Shallow flow through the 9-foot pipe further prevents upstream fish movement. An existing exposed underground utility line may require additional stabilization, incorporation into a replacement crossing structure or removal (if no longer active). The combination of two crossing structures adds complexity to this crossing site and will require additional excavation and removal. However, as at Site 19, the invert of the box culvert is submerged in a pool under normal flows by a riffle downstream, which indicates that the change in grade from upstream to downstream is not too severe to accommodate in a naturalized stream simulation. Dogwood Lane is also not a major traffic artery, making the logistics of temporary road closure less complicated. However, as at Site 19, it appears that the existing road crossing does not meet current road standards (e.g. road width, guiderails, road cover); in contrast, any replacement of the road crossing will likely be held to such standards. If inadequate road cover exists over the culvert crossing, the height of the road surface may need to be raised, which extends the length of road that would require removal and replacement. Conceptual Design As both stream crossings are on similar reaches of the high-gradient tributary; the restoration approaches are also alike. Resolving the problematic situations at both Sites 19 and 20 will follow the general principles of restoring stream continuity: (i) restore the flow of water and sediment through the crossing, (ii) re-create a stream channel that mimics adjacent reaches and renders the crossing virtually invisible to aquatic and terrestrial biota. In this sense, the stream crossing should be no more difficult to pass than any adjacent reach. The restoration design process should follow accepted approaches (e.g. Bates, K.K. and Kirn, R Guidelines for the Design of Stream / Road Crossings for Passage of Aquatic Organisms in Vermont, Vermont Department of Fish and Wildlife). The design procedure entails site investigation, hydrologic and hydraulic modeling and engineering design. The type of culvert material is a major decision driven heavily by cost concerns. Metal culverts are significantly cheaper than concrete culverts; however, metal culverts tend to have a shorter lifespan than concrete. Metal culverts also are subject to accelerated corrosion due to acidic soils, in which case, concrete culverts are preferred. Certain metal coatings are available which can extend the design-life of a metal culvert. Market-drive materials costs, design-life, and site conditions will have to be considered during the design phase to make the final decision on the type of culvert material is best for the project. The type of culvert form (i.e. closed-bottom or open-bottom) is a second major decision driven heavily by cost concerns. Open-bottom culvert designs include concrete box, concrete arch or metal arch. Closed-bottom culverts include concrete box, concrete pipe, or metal pipe. Open-bottom culverts are generally preferred from the fish-passage and stream connectivity perspective for two reasons. First, stream bed materials installed in a closed-bottom culvert are susceptible to blow-out during large flood events. Second, while buried below grade, closed-bottom culverts inherently retain some risk of becoming vertical barriers if the stream channel were to incise in the future. Open-bottom culverts are, however, significantly more expensive than closed-bottom culverts and can make or break a project with limited available funding. Unlike closed-bottom culverts, open-bottom culverts require footings, which are typically poured concrete. Princeton Hydro, LLC Page 4 of 6

5 With these considerations in mind, the current recommended conceptual design entails an openbottom metal arch culvert, with boulder step-pool features within or adjacent to the structure. Steppool features are recommended to provide fish-passable vertical transitions and long-term vertical channel stability. To ensure stability through high flows, each step will likely have to be constructed of boulders. Re-creation of continuous bank-lines will also be considered to facilitate the movement of terrestrial biota that rely on continuous riparian corridors for movement and cover and thus minimize adverse behavioral impacts or mortality due to road crossing. Photos and conceptual design are depicted in the accompanying plan. Permitting Each stream crossing should be considered separate and complete projects and permitted separately. Replacement of each of the stream crossings will likely require the following permits: BWM-GP-11 Maintenance, Testing Repair, Rehabilitation or Replacement of Water Obstructions and Encroachments (PADEP Bureau of Water Management); Joint Permit Pennsylvania State Programmatic General Permit (PASPGP-4), Permit issued by USACE Philadelphia District and PADEP; Erosion and Sediment Control Plan; NPDES Permit (National Pollutant Discharge Elimination Permit) Only required if earth disturbance exceeds 1.0 acres (not anticipated based on conceptual designs). Anticipated Range of Costs The necessary steps to advance the design and regulatory approval for a road crossing replacement are listed below along with anticipated costs (2012) based on past project experience and professional judgment. Actual costs may vary with official quotes from subcontractors, and advance input from municipal officials and regulatory agencies. Design and Permitting Princeton Hydro estimates the design and permitting for one road-stream crossing to cost approximately $25,500 $32,500. Grouping the design and permitting for both Sites 19 and 20 into one effort would yield 20-30% savings. Professional Land Survey Wetland Survey Site Investigation (Engineering / Geomorphology) Hydrology and Hydraulics Engineering Plan Preparation Preparation/Submission of Permits Regulatory Negotiation / Plan Revision Princeton Hydro, LLC Page 5 of 6

6 Construction Actual construction costs are difficult to estimate prior to the completion of a design that specifies methods, materials, time frame, regulatory obligations, design specifications, as well as market changes and material costs. Typical steps in the construction process are listed below. Based on prior project experience and professional judgment, construction cost may range $100,000 $200,000. Mobilization Traffic Control Erosion and Sediment Control Clearing for Access Demolition / Excavation Export of Material Crossing Replacement o Foundation / Wingwalls (e.g. Concrete Cast-in-Place) o Stream Bottom Construction (e.g. Boulder Step-Pool Structure) o Culvert Installation (e.g. Pre-Cast) Bank Grading / Stabilization Roadway Reconstruction Guide Rail Installation Riparian Restoration Planting Demobilization Princeton Hydro, LLC Page 6 of 6

7 Photographic Log Client: Bucks County Trout Unlimited, Inc. Site Name: Site 19, Unnamed Tributary Project Number: Site Location: Durham Twp, Bucks Co, PA Photograph ID: 1 Date: 10/22/11 Location: Funks Mill Road Direction: From North Comments: Upstream 5 RCP inlet. Bedload accumulation creates steep riffle and barrier to fish passage. Headwall is failing. Erosion is occurring along roadway embankment. Photograph ID: 2 Date: 10/22/11 Location: Funks Mill Road Direction: From South Comments: Downstream 5 RCP outlet. Existing scour pool. Page 1 of 2

8 Photographic Log Client: Bucks County Trout Unlimited, Inc. Site Name: Site 20, Unnamed Tributary Project Number: Site Location: Durham Twp, Bucks Co, PA Photograph ID: 3 Date: 6/29/2011 Location: Dogwood Lane Direction: From North Comments: Upstream inlet of 6 RCP. Bedload accumulation creates steep riffle and barrier to fish passage. Photograph ID: 4 Date: 6/29/2011 Location: Dogwood Lane Direction: From South Comments: Downstream outlet of concrete box culvert. Outlet of 6 RCP visible within. Exposed utility line in foreground. Page 2 of 2