FISH PASSAGE ALTERNATIVES ANALYSIS ON PENNYPACK CREEK AT VERREE ROAD DAM AND ROOSEVELT BOULEVARD DAM PHILADELPHIA, PENNSYLVANIA Prepared for: One Parkway, 10 th Floor 1515 Arch Street Philadelphia, PA 19102 Prepared by: 4507 North Front Street, Suite 200 Harrisburg, PA 17110 717-635-7901 URS Project No. 20497772 February 16, 2007
TABLE OF CONTENTS SECTION DESCRIPTION 1.0 INTRODUCTION...1 2.0 METHODOLOGY...1 3.0 DESCRIPTION OF DAMS......4 3.1 Verree Road Dam 3.2 Roosevelt Boulevard Dam 4.0 FISH PASSAGE ALTERNATIVES.... 6 4.1 Total Dam Removal 4.2 Dam Removal with Partial Remnants 4.3 Engineered Fishways 4.4 Bypass Channels 4.5 Rock Ramp 4.6 Partial Dam Removal / Rock Ramp 4.7 No Action 5.0 ALTERNATIVES ANALYSIS... 11 5.1 Verree Road Dam 5.2 Roosevelt Boulevard Dam LIST OF FIGURES FIGURES No. DESCRIPTION 1 Site Location Map.3 2 Verree Road Dam Plan Sheet...16 3 Roosevelt Boulevard Dam Plan Sheet...21 LIST OF TABLES TABLE No. DESCRIPTION 1 Status of Fish Blockages on Pennypack Creek. 4 2 Impact Assessment of Fish Passage Alternatives 12 3 Summary of Fish Passage Alternatives at Verree Road Dam 17 4 Summary of Fish Passage Alternatives at Roosevelt Blvd. Dam 22 LIST OF APPENDICIES APPENDIX A B DESCRIPTION Verree Road Dam Photographs Roosevelt Boulevard Photographs
1.0. INTRODUCTION Over the last several years, there has been tremendous interest in restoring anadromous fish passage to Pennypack Creek, primarily hickory shad and river herring. The removal of fish migration barriers will allow these species to access the upper watershed for spawning. These species provide a forage base for larger game fish most notably striped bass or rockfish. Barrier removal and/or fish passage provisions on Pennypack Creek should have a direct benefit to the striped bass fishery. In addition, hickory shad also provide a unique recreational fishery during the spawning migration in the spring of the year. Since 2003, the Pennsylvania Fish and Boat Commission (PFBC) has stocked over 14 million hickory shad fry in the Pennypack Creek watershed in an attempt to restore a viable fishery. The Fairmount Park Commission (FPC) has authorized URS Corporation (URS) to prepare an analysis of fish passage alternatives at two dams owned by FPC; Verree Road Dam and Roosevelt Boulevard Dam. The location of these dams is shown on Figure 1. As shown on Table 1, these dams are located 5.7 and 9 miles respectively from the confluence with the Delaware River. Most dams trap sediment within the stream channel and along the flooplain. The volume and type of sediment retained varies and is influenced by numerous factors including: geology, land use, length of time the dam has been in place, condition of the dam, and watershed morphology (valley width and channel slope). All of these factors need to be investigated when considering fish passage alternatives at dams. The fact that the two dams are historic structures will be a factor in FPC s decision about which fish passage methods to implement. 2.0. METHODOLOGY In order to analyze various alternatives to provide anadromous fish passage, each project location was surveyed on December 18 and 19, 2006. Information from the United States Geological Survey (USGS) streamflow gauge (located 400 feet downstream of the Rhawn Street bridge) on the day of the survey was a stage of 2.5 feet and flow at 48 cubic feet per second (cfs). The survey included a general topographic survey, channel profile and one cross section above and below each dam to show existing conditions. A small boat was used to survey the profile upstream of the dam to examine stream and channel conditions. Each dam was also examined to determine safety deficiencies. Digital photographs were taken of the dam from numerous vantage points around the dam and are included in Appendices A and B. Upon completing the field work, the survey data was processed to prepare a base plan of each dam site. The survey data of each dam was processed in AutoCADD to graphically show site conditions including plan view, channel profile and cross sections are shown on Figures 2 and 3. Numerous factors were evaluated in the analysis of fish passage alternatives including: Current condition of the dams and surrounding structures Current uses of the dams Historic value of the dams 1 Fish Passage Alternatives Analysis on Pennypack Creek,
The nature, extent and volume of sediment The efficacy of each fish passage alternative to restore passage for hickory shad and river herring as well as resident fish species Safety and liability concerns Long term maintenance requirements Potential impacts to surrounding environmental resources Water quality Implementation costs Recommendations have been made for fish passage at each dam based on the consideration of these factors. 2 Fish Passage Alternatives Analysis on Pennypack Creek,
3 Fish Passage Alternatives Analysis on Pennypack Creek,
TABLE 1 STATUS OF FISH BLOCKAGES ON PENNYPACK CREEK BLOCKAGE RIVER MILE (from mouth) STATUS Frankford Avenue Dam 2.1 Removed 11/06 Sewer line crossing #1 2.3 Rock ramp fish pass, scheduled for construction Spring 2007 Rhawn Street Dam 3.7 Removed 11/06 Roosevelt Boulevard Dam 5.7 Verree Road Dam 9.0 Huntington Pike Dam 11.9 Scheduled removal 7/07 Spring Dam 12.9 Removed 12/05 3.0. DESCRIPTION OF DAMS Both dams evaluated for fish passage are owned by FPC and are located in Pennypack Park, part of the Fairmount Park system. Descriptions of both dams are provided. Reference to right or left stream bank is from a perspective looking downstream. Photographs of the Verree Road Dam and Roosevelt Boulevard Dam are provided in Appendix A and B respectively. 3.1 Verree Road Dam The Verree Road Dam is located 500 feet upstream of Verree Road. The site is accessible from Verree Road by a macadam trail along the right (southwestern) stream bank. The dam is approximately 130 feet wide and approximately 9 feet high from the top of the dam to the foundation. Remnants of an earthen embankment mill race is located along the right bank downstream of the dam, however most of the mill race has been filled in. On December 18, 2006, URS surveyed a 1,300 foot channel profile through the dam. The change in water surface upstream of the dam to immediately downstream of the dam was 4.28 feet during the survey. Water depths behind the dam ranged between 1 and 6 feet. The scour pool below the dam is approximately 3 feet deep. A cross section was surveyed 100 feet upstream of the dam and another was surveyed 100 feet downstream of the dam. These cross sections are shown on the attached plan sheet and graphically show typical channel conditions at these locations. The dam is constructed of mortared rock which was acquired from a small quarry located within the immediate project area. The channel upstream of the dam consists of a large oxbow to the west as shown on Figure 1. The majority of the left bank along this oxbow is steep with exposed rock outcrop. The interior of the oxbow is flat and was reportedly a shallow pond used for recreational boating when the dam was constructed. This area has since been naturally filled in through sediment accumulation and was restored as a wetland meadow (see photo 8, Appendix 4 Fish Passage Alternatives Analysis on Pennypack Creek,
A). There are very large, mature trees lining both banks throughout the impoundment and adjacent park areas. 5 Fish Passage Alternatives Analysis on Pennypack Creek,
The dam currently serves no function and does have noticeable sediment accumulation. The dam has no appreciable flood storage capacity as it is a run-of- the-river dam with a relatively shallow impoundment due to its setting (narrow valley) and impounded sediment. The impounded sediment that exists appears to be primarily sand and fine gravel and is thickest along the left bank immediately upstream of the dam. It is estimated that the depth of sediment is six feet immediately upstream of the dam (along the left bank) and tapers upstream of the dam approximately 1,500 feet. Fish passage alternatives that involve total or partial removal of the dam will need to address the mobilization of impounded sediment. Pennypack Creek is stocked with trout in the spring and fall of the year and the Verree Road Dam is a popular fishing spot during these times due to the deeper water conditions above the dam. Aquatic habitat is limited throughout the impoundment as a result of poor substrate. There is suitable habitat along the deeper portions of the channel and overhead cover is abundant as a result of large trees and submerged woody debris. There is also several hundred feet of eroded stream banks within the impoundment area. There are no dam safety reports available from Pennsylvania Department of Environmental protection (PADEP) Division of Dam Safety records. There are several locations along the dam face where water is seeping through the dam as shown on photo 5, Appendix A. At the time of the survey, there were three large trees lodged on the dam with a large tangle of woody debris near the center of the dam (see Appendix A photos 1, 2, and 3). There is currently a breach around the left side of the dam which has eroded into the bank (see Appendix A photos 1 and 4). Concrete was also poured around the left dam abutment and stone masonry wall and the stone masonry joints have been repointed. It was reported that the right bank had breached in the past and that this breach was filled and armored with large rock to protect the bank. It appears that the dam has and will continue to require regular maintenance. 3.2 Roosevelt Boulevard Dam The Roosevelt Boulevard Dam is located approximately 280 feet upstream of Roosevelt Boulevard (Route 1). The dam is accessible from Winchester Avenue (300 feet east of Roosevelt Boulevard) via a utility road which leads to the Park recreation path as shown on Figure 1. The survey of the Roosevelt Boulevard dam was completed on December 19, 2006. The profile shows a 4 foot vertical change in water surface over the dam. The scour pool near the center of the dam is 3 feet deep. The dam is 110 feet wide and approximately 8 feet high from the top of the dam to the foundation. The dam is constructed of mortared stone masonry. There is a 2 foot wide concrete apron along the foundation of the dam to prevent scour. A stone masonry wall is located along the left bank of the dam which extends 50 feet downstream. A stone masonry wall along the entire right bank extends from the Route 1 bridge, past the edge of the dam to a point 400 feet upstream. There is an existing sewer line utility along the right bank between the stone masonry wall and edge of the valley as shown on photo 7 for the dam. There is a pedestrian bridge which crosses the stream approximately 200 feet upstream of the dam and is associated with the park trail network. The right bank is also cleared as there is a sewer line which parallels the right or south bank. 6 Fish Passage Alternatives Analysis on Pennypack Creek,
The dam currently serves no function and does have noticeable sediment accumulation. The dam has no appreciable flood storage capacity due to its setting (narrow valley) and extent of impounded sediment. There appears to be a natural berm along the left bank immediately upstream of the dam. This berm is shown on the upstream cross section and consists of sand. The channel planform is such that the left bank represents the depositional side of the stream due to a slight meander to the left (southerly channel flow from the south to the east). Sediment within the channel is also highly visible along the left bank. The sediment appears to be primarily sand and fine gravel and is greatest along the left bank between the dam and the pedestrian bridge as shown in Appendix B, photo 6. The estimated depth of sediment within this area of the impoundment is between five and six feet immediately upstream of the dam. Another area of sediment deposition was noted approximately 500 feet upstream along the right bank. This sediment bar is associated with an unnamed tributary which enters the impoundment along the right bank. The estimated depth of sediment in this area of the impoundment is three to four feet. Fish passage alternatives that involve total or partial removal of the Roosevelt Boulevard dam will need to address the mobilization of impounded sediment. Aquatic habitat is limited throughout the impoundment as a result of poor substrate. There is suitable habitat along the deeper portions of the channel and overhead cover is abundant as a result of large trees and submerged woody debris as shown in Appendix B, photo 8. There is also several hundred feet of eroded stream banks within the impoundment area. As with the Verree Road dam, Pennypack Creek above the Roosevelt Boulevard Dam is stocked with trout and is a popular seasonal fishery. There are no dam safety reports available from PADEP records for the Roosevelt Boulevard dam. It appears that a concrete cap was installed on top of the dam and portions of this cap along the right bank have since fallen off and flow over the dam is concentrated at this location. Water is also seeping under the concrete cap along the left bank. Portions of the wall upstream and downstream of the dam along the right bank are undermined and failing. Maintenance of the dam is needed to prevent deterioration of conditions. 4.0. FISH PASSAGE ALTERNATIVES This section describes the fish passage alternatives that were evaluated for the Verree Road and Roosevelt Boulevard dams. The following design criteria are assumed necessary for any passage alternative to be effective for the target species: channel slopes no greater than 5% Velocities which would not exceed 6 feet per second Adequate water depth for fish to swim (shad and herring cannot jump over obstacles) Adequate areas for fish to rest (shad and herring are attracted to strong currents but cannot swim long distances in swift currents) The options involving total and partial removal of dams are proven alternatives to restore fish passage including local resident fish species as well as the anadromous target species of Pennypack Creek (hickory shad and river herring). Engineered fishways have also been used in 7 Fish Passage Alternatives Analysis on Pennypack Creek,
the eastern United States for shad restoration efforts. Denil fish ladders have been used at several dams throughout the United States and Europe however their effectiveness in restoring shad passage is limited. Other more natural methods of restoring fish passage on Pennypack Creek were also evaluated including: bypass channels, rock ramps and the combination of partially removing the dams in combination with rock ramps. These other fish passage alternatives have been used in the United States and Europe for various fish species and are only now being considered for shad passage. To date there has only been one bypass channel used for shad restoration (Heishman s Mill along the Conodoguinet Creek in Carlisle PA). The effectiveness of this project has not yet been determined. The successful use of rock ramps to provide fish passage is well documented especially in New England and Europe with the target species being local resident species as well as river herring and anadromous salmonids. There is currently an approved design for a rock ramp fishway on the Pennypack Creek which is planned for construction in Spring 2007. The implementation of some of the fish passage alternatives discussed in this report as it relates to hickory shad is relatively new. The effectiveness and long term operations and maintenance of these fish passage alternatives (other than total or partial dam removal) is yet to be determined. 4.1 Total Dam Removal This option involves the removal of the entire dam structure. Typically a phased breach design is used to incrementally remove the dam by first creating a notch to begin dewatering of the impoundment. This approach will minimize the sudden mobilization of impounded sediment behind the dam. Subsequent sections of the dam are then removed until the entire dam within the notch is removed to the approximate original channel invert at the dam foundation. Upon complete dewatering of the impoundment, the remaining dam structure is removed on either side of the breach notch. In most projects, the dam material can usually be disposed of within the immediate project area especially if the dams were constructed with rock. The dam construction material is often used for bank protection along the stream bank both upstream of the dam in the former impoundment and downstream of the dam to fill any scour pools or eroded stream banks. The removal of dams requires an investigation of the quantity of sediment as well as the physical and chemical characteristics in order to determine potential downstream impacts from sediment mobilization. The design of dam removals should also consider potential impacts of the stream upstream of the dam. The removal of dams has also been shown to improve water quality especially in lowering water temperatures during the summer months. The removal of dams is a very effective means of restoring fish passage including local resident and seasonal anadromous species. It is possible that resident fish populations could benefit from improved genetic diversity due to the possible population isolation caused by the dams. Total dam removal restores run of river conditions and there is no longer any maintenance required by the dam owner. This alternative also eliminates any potential safety hazard associated with dams and eliminates any long term maintenance. Other stream uses are also enhanced, especially unrestricted passage by canoes and rafts. The design plans for removal 8 Fish Passage Alternatives Analysis on Pennypack Creek,
should also consider stream bank and channel stabilization and habitat improvements within the impounded area. Depending on site conditions, the removal of dams can cause future instabilities. Through the deposition of sediment along the floodplain upstream of dams, stream channels can become entrenched after dams are removed. Potential restoration options include: 1) the removal of accumulated sediments along the floodplain to create a new floodplain 2) the installation of stepped grade control structures to allow the new channel to have access to the existing floodplain (these structures need to be designed to allow fish passage) or 3) combination of sediment removal and lifting the channel bed through stepped grade control structures. The stream restoration and estimated costs assume that a detailed design and permitting approvals will be required to restore a natural and stable channel through the affected impoundment. Complete dam removal is not always a feasible option due to existing land uses, industrial and residential infrastructure in the vicinity of a dam or immediately downstream, and other uses associated with the dam (i.e. water supply). The total removal of dams should not require any long term operations and maintenance. 4.2 Dam Removal with Partial Remnants This option requires the dewatering of the impoundment as discussed previously but includes retaining at least a portion of the dam along one or both stream banks. This option typically involves removing the vast majority of the dam to provide unrestricted flow and fish passage but keeping a limited portion (several feet) of the dam in place along either or both banks. This option is often considered for dams which have some important historical significance. With portions of the dam in place, some historical value is retained with respect to the visual setting of where the dam was located. Educational kiosks are often prepared showing photographs and other features of the dam. This option is also effective in providing fish passage for both local resident species and seasonal anadromous species. The same issues exist with sediment mobilization upstream of the dam and need to be investigated as well as follow-up stream restoration and stabilization. The future integrity of those sections of dam not removed is unknown but typically include some form of rock fortification at the foundation. Over time these remaining sections of the dam may require some routine maintenance and/or additional rock protection to protect those sections of the dam which were retained for historic interpretation. 4.3 Engineered Fishways Fishways, most commonly referred to as fish ladders but also known as fish passes, are structures placed on or around human-made barriers to assist the natural movement of fish around or over the barrier. Most fishways enable fish to pass around dams or other barriers through a series of relatively low, man-made steps (hence the term ladder). A critical design element is the ability to attract fish to the downstream entrance of the fishway. The velocity of water falling over the steps has to be great enough to attract the fish to the ladder, but it cannot be so great as to wash fish back downstream or to exhaust them to the point where they cannot continue their journey upriver. Denil fishways are the most common fishway used in shad and herring restoration since this design is used for target species which cannot jump between steep, vertical drops in the fishway. 9 Fish Passage Alternatives Analysis on Pennypack Creek,
A denil fishway is a type of fish ladder designed with a series of sloped channels. The fishway can be constructed with an overall slope of 10 to 25 percent. Denil fishways are constructed with poured concrete. Wooden V shaped baffles are placed at regular intervals inside the fish ladder, and are usually constructed with a 45 percent slope. A narrow entrance creates high water velocity to attract fish. Resting pools may be located between long segments of the fishway. A very important design consideration is the attraction flow of the fishway below the dam. In order to be effective, fish must be able to find and be attracted to the flow of the fish ladder entrance. The results of fish ladders providing shad passage are highly variable. The approximate construction costs of denil fishways is $65,000 to 75,000 per vertical foot of barrier to overcome. These types of fishways require regular maintenance which primarily involves the regular removal of debris especially during times of fish migration. The effectiveness in providing passage for the project target species has not been shown to be high. 4.4 Bypass Channels Bypass channels involve the creation of a separate channel linking the upstream pool with the channel below the dam. This fish passage alternative has been used in Europe for different target species and has not been demonstrated as an acceptable fish passage alternative in the United States. The use of bypass channel requires the use of adjacent lands suitable to construct a channel of proper size and stream pattern. The outlet to the bypass channel must have sufficient flow below the dam to attract fish especially during low flow periods. Current design guidelines for shad and herring suggest channel slopes less than 5%. The design channel also needs to incorporate areas for fish to rest as they swim upstream and typically involves the use of large volumes of rock to provide added bank and channel protection. The channel has to be constructed to be able to handle large storm events but also be able to provide fish passage during low flow periods. As with engineered fish passage the critical design element is the ability to attract fish to the entrance of the bypass channel. Bypass channels may require some regular maintenance, primarily debris removal, however the maintenance would be relatively low cost especially if the channel is easily accessible. As mentioned earlier, the implementation of bypass channels to provide fish passage for hickory shad and river herring is limited and the effectiveness of this fish passage option has yet to be determined. 4.5 Rock Ramps Rock ramps can be used on low head dams (usually less than six feet) to provide fish passage over obstructions in a stream. Rock ramp fishways consist of the construction of a series of boulder arch weirs across the stream and downstream of the dam. The lowest portion of the boulder arch is located near the center of the channel where flow is concentrated and water depth is greatest. The design principle is to manipulate the channel downstream of the dam to create locally steeper gradients between a series of boulder arches or steps. Gaps are kept between the rocks near the center of each boulder arch so that fish can swim through the structure. The overall design slope is typically 1:20 or about 5%. The channel bottom is graded to provide a ramp near the dam or stream obstruction to allow fish to swim over the dam. Deeper pools and resting areas are also created between the arches. The number of boulder arches depends on the existing downstream channel slope and vertical change of water slope to overcome. Although 10 Fish Passage Alternatives Analysis on Pennypack Creek,
full width rock ramps have been found to more effective for fish passage, partial width rock ramps are an option in certain situations. The full width rock ramp would eliminate any visual attributes of a dam and would appear more like a more natural series of riffles and pools. The use of rock ramps may also involve the raising of the impounded water surface in order to provide adequate depth of water (especially during low flow periods) for fish to swim over the barrier. A partial width rock ramp along one river bank and immediately downstream of the dam could allow for some visual elements of a dam to remain (the upper one to two feet of the dam along the remaining channel opposite of the partial width ramp). Rock ramps require the use of large volumes of large rock and may require some long term maintenance of the structures to allow fish passage. The use of rock ramps in New England appears to be effective for passing river herring but the effectiveness for passing hickory shad has not yet been determined. 4.6 Partial Dam Removal/Rock Ramp In order to reduce the vertical height to overcome at a dam to provide fish passage and reduce the number of boulder arch weirs in the rock ramps, the entire upper portion of dams can be removed to reduce the elevation of the barrier. Another option included with this alternative is to create a notch in the top of the dam of suitable width and depth which would concentrate flow through the dam to attract fish movement. The notch can be installed by cutting the masonry or concrete with a masonry saw or hydraulic hammer. Additional design data would need to be collected to determine the size of the notch but it is estimated that the notch would need to be at least four feet wide and at least one foot deep. A notch would provide the required depth to allow fish to swim through the dam face instead of over the dam. The visual effect of water flowing over the dam would remain even though more flow would be concentrated through the notch. The same construction methods discussed above would be used to construct the rock ramps. Although this is a fish passage alternative which could be considered, the approval of this concept would need to be pursued with the regulatory agencies. 4.7 No Action This alternative involves keeping the dam in place and would require long term maintenance. The liabilities associated with the dam would remain which would most likely include future installation of fish passage structures. 11 Fish Passage Alternatives Analysis on Pennypack Creek,
5.0. ALTERNATIVES ANALYSIS The following section discusses the various fish passage alternatives for each dam. Implementation of any of the fish passage options will require public safety provisions along the public trails and recreational use areas adjacent to the dam sites. Tables 2 and 3 provide a summary of the advantages and disadvantages as well as impacts associated with each alternative. 12 Fish Passage Alternatives Analysis on Pennypack Creek,
TABLE 2 IMPACT ASSESSMENT OF FISH PASSAGE ALTERNATIVES Fish passage effectiveness Minimizes safety and liability concerns Verree Road Dam 1. Dam removal/stream restoration high yes yes no yes yes yes yes 2. Dam removal with partial remnant high yes yes no yes yes yes yes 3. Engineered fishways unknown no no no yes no no no 4. Bypass channels unknown no no yes no no no no 5. Rock ramps moderate yes yes no yes no no no 6. Partial dam removal/rock ramp high yes yes no yes no no yes 7. No action (dam stays in place) N/A no no yes yes no no no Roosevelt Boulevard Dam 1. Dam removal/stream restoration high yes yes no yes yes yes yes 2. Dam removal with partial remnant high yes yes no yes yes yes yes 3. Engineered fishways unknown no no no yes no no no 4. Bypass channels N/A N/A N/A N/A N/A N/A N/A N/A 5. Rock ramps high yes yes no yes no no no 6. Partial dam removal/rock ramp high yes yes no yes no no yes 7. No action (dam stays in place) N/A no no yes yes no no no Minimizes long term maintenance Minimizes impact on historic values Minimizes impact to adjacent env. resources Mazimizes containment of impounded sediment Minimizes upstream flooding impacts Maximizes water quality enhancements 13 Fish Passage Alternatives Analysis on Pennypack Creek,
5.1 Verree Road Dam Construction Access Construction access to the Verree Road Dam is relatively good. Equipment will need to utilize the Park entrance from Verree Road just south of the bridge crossing. The existing park trail can be used to access the dam site. Protection of the macadam trail from damage by construction equipment will need to be implemented. Total Dam Removal / Stream Restoration Total dam removal is a viable option and will provide numerous benefits including the desired fish passage, elimination of a potential safety hazard and associated owner liability, maintenance and water quality improvements. Removal of the Verree Road Dam would need to consider the management of sediment mobilization. The removable of the dam will result in a deeply entrenched channel throughout the impoundment. Some sections of the stream banks upstream of the dam are steep and eroding and would deteriorate if the dam were removed, as there would be limited access to the floodplain. Due to the existing unstable condition of the channel upstream of the dam, approximately 1,500 feet of stream restoration and stabilization is recommended and would add to the dam removal project costs. The associated stream restoration would address the long term mobilization of impounded sediment by creating a newly constructed channel through the entire reach within the affected impoundment. The estimated cost for total dam removal, is approximately $30,000 and the associated stream restoration would be in the range of $130,000 to $230,000 and includes design and permitting. Total project costs therefore would range between $160,000 and $260,000. Dam Removal with Partial Remnant/ Stream Restoration Removing the dam and keeping partial remnants of the dam would also be an effective alternative with respect to fish passage. Sections of the dam along either or both banks could remain in place to preserve some historical aspects of the dam. Subsequent data collection and design would determine how much of the dam would need to be removed in order to allow fish passage. As with full removal, stream restoration and channel stabilization would be required. The retainage of part of the dam would also require additional stabilization of any partial dam remnants and continued future maintenance. The cost of partial removal (majority of the dam removed) and the associated stream restoration would be similar to total dam removal option which also includes stream restoration. Engineered Fishways The construction of a fish ladder may provide the desired benefits of fish passage but has not been proven to be highly effective for shad. The best location would be along the right or west bank which is more accessible than the left bank. An engineered fishway would have a visual impact on historic features of the dam. This alternative would not mobilize upstream sediments, however the existing breach along the left bank would need to be stabilized. This option would require long term routine maintenance of the dam and fish ladder and the safety and liability 14 Fish Passage Alternatives Analysis on Pennypack Creek,
issues associated with the dam would remain. The estimated range in construction costs is $650,000 to $750,000. Bypass Channel A bypass channel could only be considered along the right bank. The use of the existing mill race was not considered in the analysis of options. The use of the mill race channel would require that the entrance to the channel be located several hundred feet downstream of the dam and it is highly unlikely that fish would be attracted to the flow. The existing channel length from the dam to the upstream end of the oxbow is approximately 2,000 feet. A bypass channel could be constructed across the oxbow to connect the upper stream entering the oxbow with the stream below the dam along the right bank. The straight line distance across the oxbow from the western end of the dam to the east bank of the upstream reach is approximately 500 feet. A constructed bypass channel would need to be at least 560 feet. The new channel would require excavation of approximately 8,000 cubic yards of soil and would have a slope of approximately 1%. A large volume of rock would be required to armor the stream banks. The effectiveness of this option is questionable as fish would need to be attracted to the flow from below the dam. The excavation of the bypass channel would also require the removal of many of the large trees in the park along the footprint of the new channel. The bypass channel would also encroach on the recently completed wetland meadow, and would require routine maintenance to ensure fish passage during the spring migration. Since the channel would lie within the existing floodplain associated with the dam, it would be expected that woody debris would accumulate in the channel. The estimated range in construction cost is $250,000 to $300,000. Rock Ramp Another more natural approach of providing fish passage is the construction of a rock ramp. A rock ramp at the Verree Road dam would require a large volume of large rock to construct at least six boulder arches and ramps. Once installed the rock ramps would create a series of cascades and pools which would extend between 120 and 200 feet downstream. The construction of a rock ramp would alter the appearance of the dam. The ramps would provide a series of cascades but the water depth over the dam would need to be raised so that fish can swim over the dam. A partial width ramp (occupying approximately one-half the channel) could possibly be used closer to the dam along the right bank which would allow for the upper portion of the dam to be visible along the left bank. Partial width ramps are considered less effective than full width ramps in passing fish. The estimated range in construction cost is $160,000 to $200,000. Partial Dam Removal / Rock Ramp A notch could be cut in the dam in conjunction with a rock ramp in order to reduce the required design vertical height. More detailed design data would need to be collected to determine the size and depth of the notch. It is estimated that the notch would need to be at least four feet wide and at least one foot deep. This notch would best be located along the right bank which would 15 Fish Passage Alternatives Analysis on Pennypack Creek,
be the outside of the meander. Fewer boulder arches and rock ramp material would be required if a notch in the dam is made. Likewise the upper course or layer of rock along the top of the dam could conceivably be removed in order to reduce the vertical height to overcome. More detailed information would need to be collected to determine the stability of the dam if the upper portion would need to be removed. Long term maintenance would be required with this option and would include the continued maintenance of the remainder of the dam and also the regular removal of any debris which would be lodged in the notch. Recommendations Based on the data collected at the Verree Road Dam, it appears that the best fish passage options would be: 1) total dam removal at Verree Road Dam, with associated stream restoration and stabilization measures, or 2) the partial dam removal (upper portion of dam or notch in top of dam) with a rock ramp. 16 Fish Passage Alternatives Analysis on Pennypack Creek,
16 Fish Passage Alternatives Analysis on Pennypack Creek,
TABLE 3 SUMMARY OF FISH PASSAGE ALTERNATIVES AT VERREE ROAD DAM ALTERNATIVE ADVANTAGE DISADVANTAGE APPROX.COST 1. Dam removal /Stream Restoration 2. Dam Removal with Partial Remant /Stream Restoration 3. Engineered Fishways -Very effective for fish passage -Eliminates long term maintenance -Eliminates safety hazard and owner liability -Improves aquatic habitat of channel within impoundment -Reduction of localized flooding -Very effective for fish passage - Retains some visual aspects of historic dam features -Reduction of localized flooding -Retains existing uses and historic values associated with dam -No sediment mobilization 4. Bypass channels -No mobilization of impounded sediment -Protects historic features of dam 5. Rock Ramp* -Maintains appearance of dam setting (upstream impoundment) -More natural in appearance -No sediment mobilization 6. Partial dam removal/rock ramp* -Retains some visual aspects of historic dam features -Maintains existing seasonal fishery resource -Minimal sediment mobilization 7. No Action -Maintains historic values of dam and existing uses -Adverse impact to historic resource -Elimination of existing seasonal fishery resource -Additional stream restoration will be required upstream of dam, accessibility is poor -Some long term maintenance may be required -Elimination of existing seasonal fishery resource -Future integrity of remaining sections of dam may be comprised -Additional stream restoration will be required upstream of dam -Requires long term maintenance (fishway and dam) -Impacts visual aesthetics of dam -Safety and liability issues remain -Effectiveness unknown -Requires long term operations and maintenance -May restrict some park uses -Would require removal of large trees and impacts to recently completed wet meadow -Impacts historic appearance of dam from downstream -Ramps could increase frequency of upstream flooding -Aquatic habitat of channel within impoundment not improved -Some visual aspects of dam will be lost -Aquatic habitat of channel within impoundment not improved -Routine maintenance of remaining dam is required -Fish barrier remains -Requires maintenance -Owner liability continues -Safety hazard remains Dam removal $30,000 Stream restoration $100,000 to $200,000 Dam removal $25,000 Stream restoration $100,000 to $200,000 $650,000 to $750,000 $250,000 to $300,000 $180,000 to $220,000 (assumes 1400 ton of rock @ $100/ton) $160,000 to $200,000 (assumes 1200 ton of rock @$100/ton) Average maintenance cost. $5,000/yr * Rock ramps require large volumes of large rock and special handling requirements for delivery. Construction costs are directly influenced by the volume of rock needed and travel distance from the source of rock. 17 Fish Passage Alternatives Analysis on Pennypack Creek,
5.2 Roosevelt Boulevard Dam Construction Access The Roosevelt Boulevard dam is accessible from Winchester Avenue as shown on Figure 1. A macadam road can be used between Winchester Avenue and Pennypack Park recreational path. Construction access to the Roosevelt Boulevard dam will require additional consideration to improve access and protect the existing trail and public safety. The intersection of the macadam lane and the trail will need to be improved so that construction equipment and/or materials can be mobilized to the dam. The existing park trail will also need to be protected to prevent damage during daily construction ingress and egress. Total Dam Removal / Stream Restoration The removal of the Roosevelt Boulevard Dam would provide unrestricted fish passage. The removal of the entire dam would however jeopardize the masonry stone wall along the right bank which is already undermined in several places. Complete dam removal would need to consider additional rock protection of the stone masonry wall and pedestrian bridge abutments. Removal of the Roosevelt Boulevard dam would need to consider the management of sediment mobilization. The removal of the dam will result in a deeply entrenched channel throughout the impoundment. Some sections of the stream banks upstream of the dam are steep and eroding and would deteriorate if the dam were removed as there would be no access to any floodplain. Due to the existing unstable condition of the channel upstream of the dam, stream restoration and stabilization is recommended and would add to the dam removal project costs. The associated stream restoration would address the long term mobilization of impounded sediment by creating a newly constructed channel through the impoundment. The extensive woody debris accumulation in the impoundment could be used to enhance aquatic habitat. The unnamed tributary along the right bank may also require grade control to prevent head cutting once the water level is lowered. The estimated construction cost range including dam removal and stream restoration is $140,000 to $200,000 and includes design and permitting. Dam Removal with Partial Remnant/ Stream Restoration Removing the dam and keeping a partial remnant would be the better alternative in order to protect the stone masonry wall and maintain some historic features of the dam for public interpretation. At least ten feet of the dam should remain intact along the right bank in order to protect the stone masonry wall. The portion of the dam along the immediate left bank could also be left in place for additional stone wall protection. The total or partial removal of the dam will need to include sediment management, stabilization of the stone masonry wall and bank stabilization upstream. Sediment management would be accomplished through stream restoration through the impoundment area. The extensive woody debris accumulation in the impoundment could be used to enhance aquatic habitat. The unnamed tributary along the right bank may also require grade control to prevent head cutting once the water level is lowered. The cost of partial removal (majority of the dam removed) and the associated stream restoration would be similar to total dam removal option which also includes stream restoration. 18 Fish Passage Alternatives Analysis on Pennypack Creek,
Engineered Fishway Construction access for a fishway is better from the north or left bank. The construction of a fish ladder may provide the desired benefits of fish passage but has not been proven to be highly effective for shad. In considering the stream planform, the best location for the fishway would be along the right or south bank, however a ladder along the left bank may also be feasible. The left bank is the depositional side of the stream however and would require additional maintenance (periodic sediment removal from the upstream side of fishway entrance. The construction of a fish ladder at the dam would have a visual impact on historic features. This alternative would not mobilize upstream sediments but would need to include stabilization of the stone masonry wall and repair to the concrete cap on the dam. This option would require long term routine maintenance of the dam and fish ladder and the safety and liability issues associated with the dam would remain. The estimated range of construction cost is $585,000 to $675,000. Bypass Channel A bypass channel does not appear to be a feasible option due to the narrow valley conditions. A bypass channel would also impact recreational use in the park by preventing access to the pedestrian bridge. Rock Ramp A rock ramp is feasible and would require a large volume of large rock to construct at least 6 and possibly 7 ramps. The construction of a rock ramp would alter the appearance of the dam. Once installed, the rock ramps would create a series of cascades and pools which would extend at least 150 feet downstream of the dam. A partial width ramp (approximately one half the channel width) could be used along the right bank which would allow the dam to be visible along the left bank. This option would require the stabilization of stone masonry wall along the right bank and also repairs to the concrete cap on top of the dam. Another requirement of using a rock ramp at the Roosevelt Boulevard Dam is additional rock protection along the outside of the southern stone masonry wall (side of wall not facing stream). The existing stone wall is stepped down at the dam. The rock ramp essentially raises the channel invert downstream of the dam and the water surface invert immediately downstream of the dam will be raised by approximately 5 feet to allow fish to swim over the dam. The raising of the downstream water surface will allow flood flow over and around the stone wall along the right bank where the sewer line is located. This flood flow could scour the cover material over the sewer without added rock protection over the sewer line. Provisions for flood flow would also need to be considered to allow water to return to the stream as flood waters recede. Partial Dam Removal / Rock Ramp Partial removal of the dam along with a rock ramp is likely to provide fish passage. A notch in the dam along the south side could also be constructed which would lower the impoundment water surface and reduce the overall height required to get fish passage over the dam. More detailed design data would need to be collected to determine the size and depth of the notch. It is estimated that the notch would need to be at least four feet wide and at least one foot deep. This 19 Fish Passage Alternatives Analysis on Pennypack Creek,
notch would best be located along the right bank which would be the outside of the meander. Fewer boulder arches and rock ramp material would be required if a notch in the dam is made. Likewise, the remaining concrete cap and upper course or layer of rock along the top of the dam could conceivably be removed in order to reduce the vertical height to overcome. More detailed information would need to be collected to determine the stability of the dam if the upper portion of the dame was removed. Long term maintenance would be required with this option and would include the continued maintenance of the remainder of the dam and also the regular removal of any debris which would be lodged in the notch. Recommendations At Roosevelt Boulevard Dam, dam removal with partial remnant and stream restoration appears to be the best option (keeping a portion of dam intact along the right bank). The removal of the entire dam may jeopardize the integrity of the stone masonry wall along the right bank. Partial dam removal (notch in dam or removal of the upper portion of the dam) in combination with a rock ramp also appears to be a viable fish passage option. 20 Fish Passage Alternatives Analysis on Pennypack Creek,
21 Fish Passage Alternatives Analysis on Pennypack Creek,
TABLE 4 SUMMARY OF FISH PASSAGE ALTERNATIVES AT ROOSEVELT BOULEVARD DAM ALTERNATIVE ADVANTAGE DISADVANTAGE APPROX.COST 1. Dam removal /Stream Restoration 2. Dam Removal with Partial Remnant /Stream Restoration 3. Engineered Fishways -Very effective for fish passage -Eliminates long term maintenance -Eliminates safety hazard and owner liability -Improves aquatic habitat of channel within impoundment -Reduction of localized flooding -Very effective for fish passage - Retains some visual aspects of historic dam features -Reduction of localized flooding Protects stone masonry wall by retaining dam along right bank -Retains existing uses and historic values associated with dam -No sediment mobilization -Adverse impact to historic resource -Stone masonry wall will need to be stabilized -Additional stream restoration will be required upstream of dam -Elimination of existing seasonal fishery resource -Some long term maintenance may be required -Future integrity of remaining sections of dam may be comprised -Additional stream restoration will be required upstream of dam -Elimination of existing seasonal fishery resource -Requires long term maintenance (fishway and dam) -Impacts visual historical aesthetics of dam -Safety and liability issues remain -Effectiveness unknown 4. Bypass channels -Not feasible -Not feasible N/A 5. Rock Ramp* -Maintains appearance of dam setting upstream (impoundment) -More natural in appearance -No sediment mobilization -Impacts historic appearance of dam -Right bank protection required outside stone masonry wall 6. Partial dam removal/rock ramp* -Retains some visual aspects of historic dam features 7. No Action Maintains historic values of dam and existing uses -Some visual aspects of dam will be lost -Fish barrier remains -Requires existing and long term maintenance -Owner liability continues -Safety hazard remains Dam removal $40,000 Stream restoration $80,000 to $160,000 Dam removal $35,000 Stream restoration $80,000 to $160,000 $585,000 to $675,000 $160,000 to $200,000 (assumes 1200 ton of rock @$100/ton) $140,000 to $180,000 (assumes 1000 ton of rock @$100/ton) Average maintenance cost. $5,000/yr * Rock ramps require large volumes of large rock and special handling requirements for delivery. Construction costs are directly influenced by the volume of rock needed and travel distance from the source of rock. 22 Fish Passage Alternatives Analysis on Pennypack Creek,
APPENDIX A VERREE ROAD DAM PHOTOGRAPHS
Fish Passage Alternative Analysis at Verree Road Dam Appendix A PHOTOGRAPHIC LOG Stream: Pennypack Creek Site Location: Verree Road Dam Project No. Photo No. Date: 1 12/18/06 Direction Photo Taken: East towards left bank 20497772 Description: Large woody debris lodged on dam breast. The left bank breach and bank erosion is visible. Photo No. Date: 2 12/18/06 Direction Photo Taken: North Description: View of dam looking upstream
Fish Passage Alternative Analysis at Verree Road Dam Appendix A PHOTOGRAPHIC LOG Stream: Pennypack Creek Site Location: Verree Road Dam Project No. Photo No. Date: 3 12/18/06 Direction Photo Taken: South 20497772 Description: View looking downstream. Photo shows woody debris accumulation on top of the dam and impounded sediment along the left bank.. Photo No. Date: 4 12/18/06 Direction Photo Taken: North Description: Close up photo from dam looking toward the left bank. The extent of the breach around the left bank of the dam is visible.
Fish Passage Alternative Analysis at Verree Road Dam Appendix A PHOTOGRAPHIC LOG Stream: Pennypack Creek Site Location: Verree Road Dam Project No. Photo No. Date: 5 12/18/06 Direction Photo Taken: North 20497772 Description: View of the left side of the dam facing upstream where the stone masonry wall ties into the dam. The dam is seeping at this location. Photo No. Date: 6 12/18/06 Direction Photo Taken: West Description: View of stream approximately 960 feet upstream of dam. The stream bank on the left side of photo is steep and eroding.
Fish Passage Alternative Analysis at Verree Road Dam Appendix A PHOTOGRAPHIC LOG Stream: Pennypack Creek Site Location: Verree Road Dam Project No. Photo No. Date: 7 12/18/06 Direction Photo Taken: North 20497772 Description: View looking upstream at dam.of masonry arch feature along the right bank. Wooden planks are placed across the opening along the upstream side. The use of this structure is unknown. Photo No. Date: 8 12/18/06 Direction Photo Taken: North Description: This area is located within the oxbow upstream of the dam and was once a pool used for recreation. The area has since filled in with sediment. The Fairmount Park Commission has restored this former impoundment as a wetland meadow.
APPENDIX B ROOSEVELT BOULEVARD DAM PHOTOGRAPHS
Fish Passage Alternative Analysis at Roosevelt Boulevard Dam Appendix B PHOTOGRAPHIC LOG Stream: Pennypack Creek Site Location: Roosevelt Boulevard Dam Project No. Photo No. Date: 1 12/19/06 Direction Photo Taken: West 20497772 Description: View looking from under the Route 1 bridge looking upstream towards dam. Photo No. Date: 2 12/19/06 Direction Photo Taken: East Description: View looking upstream at dam. Flow is concentrated along the right bank.
Fish Passage Alternative Analysis at Roosevelt Boulevard Dam Appendix B PHOTOGRAPHIC LOG Stream: Pennypack Creek Site Location: Roosevelt Boulevard Dam Project No. Photo No. Date: 3 12/19/06 Direction Photo Taken: South 20497772 Description: View looking upstream towards dam showing the stone masonry wall. The concrete cap on the dam requires some maintenance. Photo No. Date: 4 12/19/06 Direction Photo Taken: South Description: View looking across dam showing stone wall foundation failure.
Fish Passage Alternative Analysis at Roosevelt Boulevard Dam Appendix B PHOTOGRAPHIC LOG Stream: Pennypack Creek Site Location: Roosevelt Boulevard Dam Project No. Photo No. Date: 5 12/19/06 Direction Photo Taken: East 20497772 Description: View from pedestrian bridge looking downstream towards dam. Note stone masonry wall along entire right bank Photo No. Date: 6 12/19/06 Direction Photo Taken: Southwest Description: Significant sediment accumulation along the left bank immediately upstream of dam
Fish Passage Alternative Analysis at Roosevelt Boulevard Dam Appendix B PHOTOGRAPHIC LOG Stream: Pennypack Creek Site Location: Roosevelt Boulevard Dam Project No. Photo No. Date: 7 12/19/06 Direction Photo Taken: East 20497772 Description: View of right bank looking downstream. A sewer line utility is located between the stone masonry wall and edge of valley. Photo No. Date: 8 12/19/06 Direction Photo Taken: East Description: View looking downstream along right bank towards pedestrian bridge