search
WP_Query Object
(
    [query] => Array
        (
            [tag] => habitat-restoration
        )

    [query_vars] => Array
        (
            [tag] => habitat-restoration
            [error] => 
            [m] => 
            [p] => 0
            [post_parent] => 
            [subpost] => 
            [subpost_id] => 
            [attachment] => 
            [attachment_id] => 0
            [name] => 
            [pagename] => 
            [page_id] => 0
            [second] => 
            [minute] => 
            [hour] => 
            [day] => 0
            [monthnum] => 0
            [year] => 0
            [w] => 0
            [category_name] => engineering
            [cat] => 31
            [tag_id] => 509
            [author] => 
            [author_name] => 
            [feed] => 
            [tb] => 
            [paged] => 1
            [meta_key] => 
            [meta_value] => 
            [preview] => 
            [s] => 
            [sentence] => 
            [title] => 
            [fields] => all
            [menu_order] => 
            [embed] => 
            [category__in] => Array
                (
                    [0] => 31
                )

            [category__not_in] => Array
                (
                )

            [category__and] => Array
                (
                )

            [post__in] => Array
                (
                )

            [post__not_in] => Array
                (
                )

            [post_name__in] => Array
                (
                )

            [tag__in] => Array
                (
                )

            [tag__not_in] => Array
                (
                )

            [tag__and] => Array
                (
                )

            [tag_slug__in] => Array
                (
                    [0] => habitat-restoration
                )

            [tag_slug__and] => Array
                (
                )

            [post_parent__in] => Array
                (
                )

            [post_parent__not_in] => Array
                (
                )

            [author__in] => Array
                (
                )

            [author__not_in] => Array
                (
                )

            [search_columns] => Array
                (
                )

            [ignore_sticky_posts] => 
            [suppress_filters] => 
            [cache_results] => 1
            [update_post_term_cache] => 1
            [update_menu_item_cache] => 
            [lazy_load_term_meta] => 1
            [update_post_meta_cache] => 1
            [post_type] => 
            [posts_per_page] => 10
            [nopaging] => 
            [comments_per_page] => 5
            [no_found_rows] => 
            [order] => DESC
        )

    [tax_query] => WP_Tax_Query Object
        (
            [queries] => Array
                (
                    [0] => Array
                        (
                            [taxonomy] => category
                            [terms] => Array
                                (
                                    [0] => 31
                                )

                            [field] => term_id
                            [operator] => IN
                            [include_children] => 
                        )

                    [1] => Array
                        (
                            [taxonomy] => post_tag
                            [terms] => Array
                                (
                                    [0] => habitat-restoration
                                )

                            [field] => slug
                            [operator] => IN
                            [include_children] => 1
                        )

                )

            [relation] => AND
            [table_aliases:protected] => Array
                (
                    [0] => ph_term_relationships
                    [1] => tt1
                )

            [queried_terms] => Array
                (
                    [category] => Array
                        (
                            [terms] => Array
                                (
                                    [0] => 31
                                )

                            [field] => term_id
                        )

                    [post_tag] => Array
                        (
                            [terms] => Array
                                (
                                    [0] => habitat-restoration
                                )

                            [field] => slug
                        )

                )

            [primary_table] => ph_posts
            [primary_id_column] => ID
        )

    [meta_query] => WP_Meta_Query Object
        (
            [queries] => Array
                (
                )

            [relation] => 
            [meta_table] => 
            [meta_id_column] => 
            [primary_table] => 
            [primary_id_column] => 
            [table_aliases:protected] => Array
                (
                )

            [clauses:protected] => Array
                (
                )

            [has_or_relation:protected] => 
        )

    [date_query] => 
    [queried_object] => WP_Term Object
        (
            [term_id] => 509
            [name] => habitat restoration
            [slug] => habitat-restoration
            [term_group] => 0
            [term_taxonomy_id] => 509
            [taxonomy] => post_tag
            [description] => 
            [parent] => 0
            [count] => 10
            [filter] => raw
            [term_order] => 0
        )

    [queried_object_id] => 509
    [request] => SELECT SQL_CALC_FOUND_ROWS  ph_posts.ID
					 FROM ph_posts  LEFT JOIN ph_term_relationships ON (ph_posts.ID = ph_term_relationships.object_id)  LEFT JOIN ph_term_relationships AS tt1 ON (ph_posts.ID = tt1.object_id)
					 WHERE 1=1  AND ( 
  ph_term_relationships.term_taxonomy_id IN (31) 
  AND 
  tt1.term_taxonomy_id IN (509)
) AND ((ph_posts.post_type = 'post' AND (ph_posts.post_status = 'publish' OR ph_posts.post_status = 'acf-disabled')))
					 GROUP BY ph_posts.ID
					 ORDER BY ph_posts.menu_order, ph_posts.post_date DESC
					 LIMIT 0, 10
    [posts] => Array
        (
            [0] => WP_Post Object
                (
                    [ID] => 10290
                    [post_author] => 1
                    [post_date] => 2022-02-17 19:39:19
                    [post_date_gmt] => 2022-02-17 19:39:19
                    [post_content] => 

The Aquetong Creek Restoration Project is situated within the former basin of Aquetong Lake, which was a 15- acre impoundment formed in 1870 by the construction of an earthen dam on Aquetong Creek. The cold-water limestone spring, which flows at a rate of about 2,000 gallons per minute at approximately 53ºf, is known to be the largest of its kind in the 5-county Philadelphia region, and one of the largest in the state of Pennsylvania.

In 2015, the Township of Solebury commenced the restoration of Aquetong Spring Park, first with a dam breach followed by a large stream restoration, reforestation, and invasive species removal. In September, the park was officially reopened to the public following a ribbon cutting ceremony. The event featured a blessing from the Lenni-Lenape Turtle Clan, the original inhabitants of the land.

 

SITE HISTORY

Prior to European settlement, the Lenni-Lenape Tribe inhabited a village close to the spring and designated the spring “Aquetong”, meaning “at the spring among the bushes." After an outbreak of smallpox, however, the tribe abandoned the village. William Penn acquired Aquetong Spring in the early 1680’s as part of his peaceful treaty with Lenni-Lenape. The park land transferred hands many times before it was owned by Aquetong Township.

The dependability of the water flow made the Aquetong Creek an ideal location for mills. As of the early 1800’s, Aquetong Spring is known to have supplied enough water to turn two grist mills regularly throughout the year, and to have concurrently powered numerous mills including a paper mill, a fulling mill, two merchant mills, four sawmills, and an oil mill.

Around 1870, the 15-acre Aquetong Lake was created by constructing a dam at the east end of the property. This provided additional power for the local mills and a recreation area for the public. A fish hatchery was constructed at the base of the spring outfall, portions of which can still be viewed today. Shad, brook trout, and terrapin turtles were raised in the hatchery, which was available for public viewing at a cost of 25 cents per person.

Then, in 1993, the Pennsylvania Fish and Boat Commission acquired the property. A few years later, with the support of Bucks County Trout Unlimited, Solebury Township began negotiating to obtain ownership of the site. Around 1996, the State performed emergency repairs on the dam; a six-foot section of the outlet structure was removed in order to take pressure off the aging barrier. This lowered the level of the lake and added about 80 feet of wetlands to the western shoreline. However, it was recognized that a complete repair of the dam could cost over $1 million and might not be the best choice for the environment.

In 2009, after almost 15 years of negotiations, Solebury Township gained control of the property, with the goal of preserving this important natural resource. It purchased the lake and surrounding properties from the state and obtained a 25-year lease. The Township’s total costs were substantially reduced because it received a large credit in exchange for its commitment to repair the dam in the future, as well as funding from the Bucks County Natural Areas Program toward the purchase.

Following the purchase, the Township engaged in a five-year process of community outreach and consultation with environmental experts in which it considered alternatives for the Aquetong Lake dam. Choices included rebuilding the dam in its then-current form, creating a smaller lake with a cold-water bypass into Aquetong Creek, or breaching the dam and restoring a free-flowing stream. Ultimately, recognizing that the lake was a thermal reservoir which introduced warm water into Aquetong Creek and eventually into the streams and river, the Township decided to breach rather than restore the dam, and return the site to its natural state.

[caption id="attachment_10303" align="aligncenter" width="832"] The Aquetong Creek restoration site is located in Solebury Township, Bucks County, PA, and encompasses the boundaries of the former Aquetong Lake. The Lake was a 15-acre impoundment formed in 1870 by the construction of an earthen dam on Aquetong Creek. The Creek flows approximately 2.5 miles from Ingham Spring to join with the Delaware River in New Hope, PA.[/caption]  

RESTORATION WORK

The Aquetong Restoration Project got underway in 2015, and Solebury Township breached the historic mill dam in Aquetong Spring Park to convert the former lake into a natural area with a free-flowing, cold water stream capable of supporting native brook trout.

After the dam breach, areas of active erosion were observed along the mainstem and a major tributary of Aquetong Creek. The steep, eroding banks, increased the sediment load to the Creek's sensitive aquatic habitat.

As with most dam removal projects, a degree of stewardship is necessary to enhance the establishment of desirable, beneficial vegetation. Additionally, Solebury Township wanted to control invasive species in Aquetong Spring Park and replant the project area with native species.

The Township secured funding to construct riparian buffers, implement streambank stabilization measures, establish trout habitat structures within the mainstem and its tributary, control invasive species, and implement a woodland restoration plan. The project was funded by a $250,000 grant from the PA Department of Conservation and Natural Resources, with an equal match from the Township. Additional grants for the project were provided by the PA Department of Community and Economic Development and the National Fish and Wildlife Foundation.

Solebury Township contracted Princeton Hydro to design the stabilization of the stream channel and floodplains within the former impoundment, monitor the stream and wetlands before and after implementation, and obtain the permits for the restoration of the former impoundment. Princeton Hydro team members designed the restoration of the main channel and tributary to reduce channel and bank erosion while supporting the brook trout habitat.

After gathering and reviewing the existing data for the site, Princeton Hydro conducted field investigations to inform and guide the final design including surveying cross sections and performing fluvial geomorphological assessments of the existing channel. Pebble counts were performed, cross sections were analyzed, and existing hydrological data was reviewed to inform the design. Simultaneously, an invasive species control and woodland restoration plan was developed for the park.

Data collected from the site was used to develop a geomorphically-appropriate, dynamically-stable design. The proposed channel design included excavation of impounded sediment to create stable channel dimensions, the addition of gravel, cobble, and boulder substrate where original/existing channel substrates were absent or insufficient, and the installation of large wood features to create aquatic habitat and enhance stability of channel bed and banks.

The banks and riparian corridor were vegetated with native seed, shrubs and trees to ultimately create a wooded, shaded riparian buffer. The design ultimately stabilized the streambanks with features that double as trout habitat and replanted the surrounding park with native vegetation.

The project was replanted with an incredibly diverse set of native species that included:

  • herbaceous species: swamp milkweed, blue mistflower, and butterfly weed;
  • shrub species: silky dogwood, winterberry holly, and buttonbush; and
  • tree species: red maple, american hornbeam, and pin oak.
[caption id="attachment_10301" align="aligncenter" width="763"] The forested restoration area was planted with a wide variety of native tree, herbaceous and shrub species. Shown here from top left: Canada Goldenrod, New England Aster and River Birch[/caption]  

EXPANDING THE PROJECT SCOPE

In addition to restoring the stream in the former impoundment, as a part of its Strategic Master Plan for Aquetong Spring Park, Solebury Township expanded its focus of the restoration project to include another 20 acres of forested land.

For this, Solebury developed a Woodland Restoration Plan which identified over 1,000 diseased forest trees, composed mostly of ash (Fraxinus sp.) and black walnut (Juglans nigra). It was the Township’s objective to remove the hazardous trees, re-establish a native woodland community, and establish an invasive species management program.

The trees removed as a part of this effort were repurposed for the stream restoration project and used for habitat features, stream stabilization measures, and park features (i.e. benches).

[caption id="attachment_10295" align="aligncenter" width="749"] Hazardous trees were removed and repurposed in the stream restoration construction, including the log grade control structures pictured here.[/caption]  

Princeton Hydro also provided stormwater design support for adjacent areas in Aquetong Spring Park, including multiple stormwater connections to the main tributary. After completion, Princeton Hydro provided bid assistance, developed a probable cost, drafted technical specifications, and produced a bid package to assist Aquetong Township in bringing the project to construction.

This restoration success could not have been possible without the hard work of so many dedicated project partners: Aquetong Spring Advisory Council, Bucks County Trout Unlimited, Solebury Township, Aquetong Township, Simone Collins Landscape Architects, PA Department of Conservation and Natural Resources, PA Department of Community and Economic Development, the National Fish and Wildlife Foundation, Lenni-Lenape Turtle Clan, and Princeton Hydro.

Princeton Hydro specializes in the planning, design, permitting, implementing, and maintenance of ecological rehabilitation projects. To learn more about our watershed restoration services, click here.  To learn about some of our award-winning restoration projects check out our blogs about the Pin Oak Forest Conservation Area freshwater wetland restoration project:

[visual-link-preview encoded="eyJ0eXBlIjoiaW50ZXJuYWwiLCJwb3N0IjoyNzA5LCJwb3N0X2xhYmVsIjoiQXJ0aWNsZSAyNzA5IC0gUGluIE9hayBGb3Jlc3QgUmVzdG9yYXRpb24gUHJvamVjdCBXaW5zIEF3YXJkIGZvciBcIkV4Y2VsbGVuY2UgaW4gV2F0ZXIgUmVzb3VyY2VzIE1hbmFnZW1lbnRcIiIsInVybCI6IiIsImltYWdlX2lkIjo3MjU4LCJpbWFnZV91cmwiOiJodHRwczovL3ByaW5jZXRvbmh5ZHJvLmNvbS93cC1jb250ZW50L3VwbG9hZHMvMjAyMS8wMy9JTUdfMDg2OC1zY2FsZWQuanBnIiwidGl0bGUiOiJQaW4gT2FrIEZvcmVzdCBSZXN0b3JhdGlvbiBQcm9qZWN0IFdpbnMgQXdhcmQgZm9yIFwiRXhjZWxsZW5jZSBpbiBXYXRlciBSZXNvdXJjZXMgTWFuYWdlbWVudFwiIiwic3VtbWFyeSI6IkRlZ3JhZGVkIGZyZXNod2F0ZXIgd2V0bGFuZHMsIHVwbGFuZHMsIGFuZCBjaGFubmVsaXplZCBzdHJlYW1zIGhhdmUgYmVlbiB0cmFuc2Zvcm1lZCBpbnRvIHRocml2aW5nIGhhYml0YXQgdGVlbWluZyB3aXRoIHdpbGRsaWZlIGF0IHRoZSBQaW4gT2FrIEZvcmVzdCBDb25zZXJ2YXRpb24gQXJlYSBpbiBXb29kYnJpZGdlLCBOZXcgSmVyc2V5LiBBIGR5bmFtaWMgcGFydG5lcnNoaXAgYmV0d2VlbiBnb3Zlcm5tZW50IGFnZW5jaWVzLCBOR09zLCBhbmQgcHJpdmF0ZSBpbmR1c3RyeSwgd2FzIGZvcm1lZCB0byByZXN0b3JlIHRoZSBuYXR1cmFsIGZ1bmN0aW9uIGFuZCBzdGV3YXJkIHRoZSBwcm9wZXJ0eSBiYWNrIHRvIGxpZmUuIE9uIFNlcHRlbWJlciAyOCwgdGhlLi4uIiwidGVtcGxhdGUiOiJzaW1wbGUifQ=="] [post_title] => Restoring Aquetong Creek: Stream Rehabilitation, Reforestation, and Invasive Species Control [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => aquetong-creek-restoration-project [to_ping] => [pinged] => [post_modified] => 2025-10-13 15:59:18 [post_modified_gmt] => 2025-10-13 15:59:18 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=10290 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [1] => WP_Post Object ( [ID] => 9512 [post_author] => 1 [post_date] => 2021-09-25 04:11:00 [post_date_gmt] => 2021-09-25 04:11:00 [post_content] =>

Just 50 miles southeast of New York City, tucked between two municipalities, sits a 650+ acre tidal salt marsh which spans the shorelines of the South River in densely populated, highly developed Central New Jersey. The South River is the first major tributary of the Raritan River, located 8.3 miles upstream of the Raritan River’s mouth, which drains into Raritan Bay.

The Lower Raritan River and Raritan Bay make up a large part of the core of the NY-NJ Harbor and Estuary Program. Within the Raritan Estuary, the South River wetland ecosystem is one of the largest remaining wetland complexes. While the South River salt marsh ecosystem has been spared from direct development, it has been degraded in quality, and does not provide optimal habitat for wildlife or maximum flood protection for residents. This area is subject to fairly regular tidal flooding (particularly when it occurs simultaneously with a storm) and periodic—generally more severe—flooding during more significant events such as nor’easters and tropical storms. Hurricanes Irene and Sandy caused damage in the Boroughs of Sayreville and South River too.

In 2018, Princeton Hydro and Rutgers University, along with the Lower Raritan Watershed Partnership, Middlesex County, Borough of Sayreville, Borough of South River, NY/NJ Baykeeper, Raritan Riverkeeper, and the Sustainable Raritan River Initiative, secured funding from NFWF’s National Coastal Resilience Fund for the “South River Ecosystem Restoration & Flood Resiliency Enhancement Project.”

The South River Ecosystem Restoration and Flood Resiliency Enhancement Project aims to:

  • Reduce socioeconomic damages to the Boroughs of South River and Sayreville caused by storm damage, flooding, and sea level rise;

  • Transform degraded wetlands to high-quality marsh that can reduce flooding and enhance fish & wildlife habitat; and

  • Engage stakeholders in activities about coastal resilience and ecological health to maximize public outreach in the Raritan River Watershed.

For this 165-acre tidal marsh and transitional forest “eco-park,” the project team is conducting an ecosystem restoration site assessment and design. This phase of the coastal restoration project will result in a permit-ready engineering design plan that stabilizes approximately 2.5 miles of shoreline, reduces flood risk for smaller coastal storms, and enhances breeding and foraging habitat for 10 state-listed threatened and endangered avian species.

[gallery link="none" ids="9640,9642,9639"]

Project Area History

This area has experienced repeated flooding, especially during large storms. For example, coastal areas of Sayreville and South River flooded after Hurricane Floyd (1999), Tropical Storm Ernesto (2006), Hurricane Irene (2011), and Hurricane Sandy (2012). Over the last century, there have been several studies and assessments completed for the South River, many of which identify this project area as a priority location for flooding improvements. The following are key reports and studies published about the project area and surrounding communities:

  • NJ Legislature’s 71st Congress published a report, “Basinwide Water Resource Development Report on the Raritan River Basin” which focused on navigation and flood control for the entire Raritan River Basin. It discussed recommendations for flood control and local storm drainage, setting the stage for future actions.

1970s
  • NJDEP Division of Water Resources published Flood Hazard Reports for the Matchaponix Brook System and Raritan River Basin, which delineated the floodplains in the South River, and its tributaries, the Manalapan Brook and Matchaponix Brook.

1980s
  • USACE New York District released a “Survey Report for Flood Control, Raritan River Basin,” which served as a comprehensive study of the Raritan River Basin and recommended several additional studies. Although the South River was studied, none of the proposed improvements were determined to be economically feasible at that time.

  • Project area was listed as one of the Nation’s Estuaries of National Significance.

1990s
  • USACE conducted a multi-purpose study of this area. This preliminary investigation identified Federal interest in Hurricane and Storm Damage Reduction and ecosystem restoration along the South River and concluded that a 100-year level of structural protection would be technically and economically feasible.

2000s
  • USACE NYD and NJDEP released a joint draft, “Integrated Feasibility Report and Environmental Impact Statement” for the South River, Raritan River Basin, which focused on “Hurricane & Storm Damage Reduction and Ecosystem Restoration.” Because it was previously determined that there were no widespread flooding problems upstream, the study area was modified to focus on the flood-prone areas within the Boroughs of Sayreville and South River, as well as Old Bridge Township.

Towards a More Resilient South River Ecosystem

Through collaboration with our project partners and following input provided from a virtual stakeholder meeting held in December 2020, Princeton Hydro developed a conceptual design for an eco-park that incorporates habitat enhancement and restoration, and protective measures to reduce impacts from flooding while maximizing public access and utility. Public access includes trails for walking and designated areas for fishing. The eco-park can also be used for additional recreation activities such as bird watching and kayaking.

Highlights of the conceptual design include the following features:

  • Approximately two miles of trails with overlook areas, connection to fishing access, and a kayak launch.

  • ~3,000 linear feet of living shoreline, located along portions of the Washington Canal and the South River, to provide protection from erosion, reduce the wake and wave action, and provide habitat for aquatic and terrestrial organisms.

  • ~60 acres of enhanced upland forest to provide contiguous habitat areas for resident and migratory fauna.

  • A tidal channel that will connect to the existing mud flat on the southeastern part of the site and provide tidal flushing to proposed low and high marsh habitats along its banks.

  • A vegetated berm with a trail atop will extend the length of the site to help mitigate flood risk.

  • Two nesting platforms for Osprey, a species listed as “Threatened” in NJ

  • Designated nesting habitat for the Diamondback Terrapin, a species listed as “Special Concern” in NJ

Princeton Hydro specializes in the planning, design, permitting, implementing, and maintenance of ecological rehabilitation and floodplain management projects. Click here to read about a coastal rehabilitation and resiliency project we completed in New Jersey.

[post_title] => Designing an Eco-Park Along the South River [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => designing-an-eco-park-along-the-south-river [to_ping] => [pinged] => [post_modified] => 2022-05-27 14:53:54 [post_modified_gmt] => 2022-05-27 14:53:54 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=9512 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 2 [filter] => raw ) [2] => WP_Post Object ( [ID] => 1391 [post_author] => 3 [post_date] => 2018-01-24 18:33:32 [post_date_gmt] => 2018-01-24 18:33:32 [post_content] =>

Welcome to the second installment of Princeton Hydro’s multi-part blog series about aquatic organism passage.

What you'll learn:

  • How does promoting aquatic organism passage benefit ecosystems as a whole?
  • How can others, including people, benefit from aquatic organism passage?
  • How has Princeton Hydro supported it?

Fostering Ecological Balance in Food Webs

A major consequence of poorly designed culverts is the destabilization of food webs. Sufficient predators and prey must exist to maintain a balanced food web. For example, freshwater mussels (Unionidae) are a common snack among fish. A mussel’s life cycle involves using certain fish as a host for their larvae until these microscopic juveniles mature into their adult forms and drop off. During this period, the host fish will travel, effectively transporting a future food source with it. In the presence of habitat fragmentation, the isolation of these symbiotic relationships can be devastating. Some mussel species rely on a small circle of fish species as their hosts, and conversely, some fish species rely on specific mussel species as their food. If a fish species is separated from its mussel partner, food shortages owing to a declining adult mussel population can occur.

Widespread Benefits to Flora, Fauna, and People

[caption id="attachment_1394" align="alignright" width="310"] A man fly fishes as his dog sits by his side at Ken Lockwood Gorge, Hunterdon County. Photo from State of New Jersey website.[/caption] A shift in the 1980s recognized the importance of redesigning road-stream crossings for several reasons, including restoring aquatic organism passage and maintaining flood resiliency. Replacing culverts with larger structures that better facilitate the movement of both water and aquatic organisms benefit all species. Roads constructed over streams allow people to travel across natural landscapes while culverts that are fish-friendly convey water at a rate similar to the surrounding landscape, reducing scour in stream beds. Fish, as well as semi-terrestrial organisms like crabs and salamanders, can take advantage of more natural stream environments and complete their migrations. Anglers appreciate healthy, plentiful fish populations nearly as much as the fish themselves. Recreation and economic growth also improve when streams regain the aquatic biological communities once lost through habitat fragmentation. According to USFWS, for every dollar spent on restoration through the Partners for Fish and Wildlife Program and Coastal Program Restoration Project, states gain $1.90 of economic activity. Stream restoration improves fish and wildlife habitat, which directly supports and enhances recreation opportunities for outdoor enthusiasts thus resulting in increased tourism-related spending and job growth.

Aquatic Organism Passage in Action at Princeton Hydro

Princeton Hydro recently completed a project to facilitate aquatic organism passage for river herring in Red Brook in Plymouth, Massachusetts. Read all about it here! Princeton Hydro was hired by Save the Sound (formerly Connecticut Fund for the Environment) to design a fish passage project along the Noroton River through a long, perched three-barrel concrete culvert under Interstate-95. Click here to read more. For an introduction to aquatic organism passage, be sure to check out the first post in this multipart-series.

Sources: "Aquatic Organism Passage through Bridges and Culverts." Flow. Vermont Department of Environmental Conservation's Watershed Management Division, 31 Jan. 2014. Web. 14 Mar. 2017. Hoffman, R.L., Dunham, J.B., and Hansen, B.P., eds., 2012, Aquatic organism passage at road-stream crossings— Synthesis and guidelines for effectiveness monitoring: U.S. Geological Survey Open-File Report 2012-1090, 64 p. Jackson, S., 2003. "Design and Construction of Aquatic Organism Passage at Road-Stream Crossings: Ecological Considerations in the Design of River and Stream Crossings." 20-29 International Conference of Ecology and Transportation, Lake Placid, New York. Kilgore, Roger T., Bergendahl, Bart S., and Hotchkiss, Rollin H. Publication No. FHWAHIF-11-008 HEC-26. Culvert Design for Aquatic Organism Passage Hydraulic Engineering Circular Number 26. October 2010. Michigan Natural Features Inventory. Freshwater Mussels of Michigan. Michigan State University, 2005.   [post_title] => Aquatic Organism Passage: A Princeton Hydro Blog Series (Part 2) [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => aquatic-organism-passage-a-princeton-hydro-blog-series [to_ping] => [pinged] => [post_modified] => 2025-10-16 20:08:18 [post_modified_gmt] => 2025-10-16 20:08:18 [post_content_filtered] => [post_parent] => 0 [guid] => http://www.princetonhydro.com/blog/?p=1391 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [3] => WP_Post Object ( [ID] => 1246 [post_author] => 3 [post_date] => 2017-11-22 11:16:30 [post_date_gmt] => 2017-11-22 11:16:30 [post_content] =>

Introducing part one of a multi-part blog series about aquatic organism passage

What you'll learn:

  • What is aquatic organism passage?
  • Why is it important?
  • How does Princeton Hydro support it?
[caption id="attachment_1254" align="alignright" width="268"] This photo from NYS DEC demonstrates a well-designed stream crossing.[/caption] Since the US government began allotting funds for building roads in U.S. national forests in the late 1920s, hundreds of thousands of culverts were built across the country. Culverts, or drainage structures that convey water underneath a barrier such as a road or railroad, were originally built with the intention of moving water quickly and efficiently. While this goal was met, many migratory fish and other aquatic organisms could not overcome the culverts’ high-velocity flows, sending them away from their migratory destinations. If the culvert was perched, or elevated above the water surface, it would require the migratory aquatic animals to both leap upwards and fight the unnaturally fast stream current to continue their journeys. Additionally, turbulence, low flows, and debris challenged the movement of aquatic organisms. Thus, the goal of aquatic organism passage (AOP) is to maintain connectivity by allowing aquatic organisms to migrate upstream or downstream under roads. AOP “has a profound influence on the movement, distribution and abundance of populations of aquatic species in rivers and streams”. These aforementioned species include “fish, aquatic reptiles and amphibians, and the insects that live in the stream bed and are the food source for fish”.   [caption id="attachment_1255" align="alignright" width="300"] This photo from NYS DEC demonstrates a poorly-designed stream crossing.[/caption] A poorly designed culvert can harm fish populations in multiple ways. If sturgeon aren’t able to surpass it, habitat fragmentation prevails. And so, a once-connected habitat for thousands of sturgeon breaks into isolated areas where a few hundred now live. When the population was in the thousands, a disease that wiped out 80% of the population would still leave a viable number of individuals left to survive and mate; a population of a few hundred will be severely hurt by such an event. In sum, habitat fragmentation raises the risk of local extinction (extirpation) as well as extinction in general. The splintering of a large population into several smaller ones can also leave species more vulnerable to invasive species. Generally, the greater the biodiversity harbored in a population, the stronger its response will be against a disturbance. A dwindling community of a few hundred herring will likely succumb to an invasive who preys on it while a larger, more robust community of a few thousand herring has a greater chance of containing some individuals who can outcompete the invasive.

Aquatic Organism Passage in Action at Princeton Hydro

Princeton Hydro recently teamed up with Trout Unlimited to reconnect streams within a prized central-Pennsylvanian trout fishery.  Our team enabled aquatic organism passage by replacing two culverts in Pennsylvania’s Cross Fork Creek. Read about it here!

To read part two of our Aquatic Organism Passage blog series, click here!

Sources: "Aquatic Organism Passage through Bridges and Culverts." Flow. Vermont Department of Environmental Conservation's Watershed Management Division, 31 Jan. 2014. Web. 14 Mar. 2017. Hoffman, R.L., Dunham, J.B., and Hansen, B.P., eds., 2012, Aquatic organism passage at road-stream crossings— Synthesis and guidelines for effectiveness monitoring: US Geological Survey Open-File Report 2012-1090, 64p. Jackson, S., 2003. "Design and Construction of Aquatic Organism Passage at Road-Stream Crossings: Ecological Considerations in the Design of River and Stream Crossings." 20-29 International Conference of Ecology and Transportation, Lake Placid, New York. Kilgore, Roger T., Bergendahl, Bart S., and Hotchkiss, Rollin H. Publication No. FHWAHIF-11-008 HEC-26. Culvert Design for Aquatic Organism Passage Hydraulic Engineering Circular Number 26. October 2010. [post_title] => Aquatic Organism Passage: A Princeton Hydro Blog Series (Part 1) [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => aop-blog-series-1 [to_ping] => [pinged] => [post_modified] => 2025-10-16 20:08:18 [post_modified_gmt] => 2025-10-16 20:08:18 [post_content_filtered] => [post_parent] => 0 [guid] => http://www.princetonhydro.com/blog/?p=1246 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) ) [post_count] => 4 [current_post] => -1 [before_loop] => 1 [in_the_loop] => [post] => WP_Post Object ( [ID] => 10290 [post_author] => 1 [post_date] => 2022-02-17 19:39:19 [post_date_gmt] => 2022-02-17 19:39:19 [post_content] =>

The Aquetong Creek Restoration Project is situated within the former basin of Aquetong Lake, which was a 15- acre impoundment formed in 1870 by the construction of an earthen dam on Aquetong Creek. The cold-water limestone spring, which flows at a rate of about 2,000 gallons per minute at approximately 53ºf, is known to be the largest of its kind in the 5-county Philadelphia region, and one of the largest in the state of Pennsylvania.

In 2015, the Township of Solebury commenced the restoration of Aquetong Spring Park, first with a dam breach followed by a large stream restoration, reforestation, and invasive species removal. In September, the park was officially reopened to the public following a ribbon cutting ceremony. The event featured a blessing from the Lenni-Lenape Turtle Clan, the original inhabitants of the land.

 

SITE HISTORY

Prior to European settlement, the Lenni-Lenape Tribe inhabited a village close to the spring and designated the spring “Aquetong”, meaning “at the spring among the bushes." After an outbreak of smallpox, however, the tribe abandoned the village. William Penn acquired Aquetong Spring in the early 1680’s as part of his peaceful treaty with Lenni-Lenape. The park land transferred hands many times before it was owned by Aquetong Township.

The dependability of the water flow made the Aquetong Creek an ideal location for mills. As of the early 1800’s, Aquetong Spring is known to have supplied enough water to turn two grist mills regularly throughout the year, and to have concurrently powered numerous mills including a paper mill, a fulling mill, two merchant mills, four sawmills, and an oil mill.

Around 1870, the 15-acre Aquetong Lake was created by constructing a dam at the east end of the property. This provided additional power for the local mills and a recreation area for the public. A fish hatchery was constructed at the base of the spring outfall, portions of which can still be viewed today. Shad, brook trout, and terrapin turtles were raised in the hatchery, which was available for public viewing at a cost of 25 cents per person.

Then, in 1993, the Pennsylvania Fish and Boat Commission acquired the property. A few years later, with the support of Bucks County Trout Unlimited, Solebury Township began negotiating to obtain ownership of the site. Around 1996, the State performed emergency repairs on the dam; a six-foot section of the outlet structure was removed in order to take pressure off the aging barrier. This lowered the level of the lake and added about 80 feet of wetlands to the western shoreline. However, it was recognized that a complete repair of the dam could cost over $1 million and might not be the best choice for the environment.

In 2009, after almost 15 years of negotiations, Solebury Township gained control of the property, with the goal of preserving this important natural resource. It purchased the lake and surrounding properties from the state and obtained a 25-year lease. The Township’s total costs were substantially reduced because it received a large credit in exchange for its commitment to repair the dam in the future, as well as funding from the Bucks County Natural Areas Program toward the purchase.

Following the purchase, the Township engaged in a five-year process of community outreach and consultation with environmental experts in which it considered alternatives for the Aquetong Lake dam. Choices included rebuilding the dam in its then-current form, creating a smaller lake with a cold-water bypass into Aquetong Creek, or breaching the dam and restoring a free-flowing stream. Ultimately, recognizing that the lake was a thermal reservoir which introduced warm water into Aquetong Creek and eventually into the streams and river, the Township decided to breach rather than restore the dam, and return the site to its natural state.

[caption id="attachment_10303" align="aligncenter" width="832"] The Aquetong Creek restoration site is located in Solebury Township, Bucks County, PA, and encompasses the boundaries of the former Aquetong Lake. The Lake was a 15-acre impoundment formed in 1870 by the construction of an earthen dam on Aquetong Creek. The Creek flows approximately 2.5 miles from Ingham Spring to join with the Delaware River in New Hope, PA.[/caption]  

RESTORATION WORK

The Aquetong Restoration Project got underway in 2015, and Solebury Township breached the historic mill dam in Aquetong Spring Park to convert the former lake into a natural area with a free-flowing, cold water stream capable of supporting native brook trout.

After the dam breach, areas of active erosion were observed along the mainstem and a major tributary of Aquetong Creek. The steep, eroding banks, increased the sediment load to the Creek's sensitive aquatic habitat.

As with most dam removal projects, a degree of stewardship is necessary to enhance the establishment of desirable, beneficial vegetation. Additionally, Solebury Township wanted to control invasive species in Aquetong Spring Park and replant the project area with native species.

The Township secured funding to construct riparian buffers, implement streambank stabilization measures, establish trout habitat structures within the mainstem and its tributary, control invasive species, and implement a woodland restoration plan. The project was funded by a $250,000 grant from the PA Department of Conservation and Natural Resources, with an equal match from the Township. Additional grants for the project were provided by the PA Department of Community and Economic Development and the National Fish and Wildlife Foundation.

Solebury Township contracted Princeton Hydro to design the stabilization of the stream channel and floodplains within the former impoundment, monitor the stream and wetlands before and after implementation, and obtain the permits for the restoration of the former impoundment. Princeton Hydro team members designed the restoration of the main channel and tributary to reduce channel and bank erosion while supporting the brook trout habitat.

After gathering and reviewing the existing data for the site, Princeton Hydro conducted field investigations to inform and guide the final design including surveying cross sections and performing fluvial geomorphological assessments of the existing channel. Pebble counts were performed, cross sections were analyzed, and existing hydrological data was reviewed to inform the design. Simultaneously, an invasive species control and woodland restoration plan was developed for the park.

Data collected from the site was used to develop a geomorphically-appropriate, dynamically-stable design. The proposed channel design included excavation of impounded sediment to create stable channel dimensions, the addition of gravel, cobble, and boulder substrate where original/existing channel substrates were absent or insufficient, and the installation of large wood features to create aquatic habitat and enhance stability of channel bed and banks.

The banks and riparian corridor were vegetated with native seed, shrubs and trees to ultimately create a wooded, shaded riparian buffer. The design ultimately stabilized the streambanks with features that double as trout habitat and replanted the surrounding park with native vegetation.

The project was replanted with an incredibly diverse set of native species that included:

  • herbaceous species: swamp milkweed, blue mistflower, and butterfly weed;
  • shrub species: silky dogwood, winterberry holly, and buttonbush; and
  • tree species: red maple, american hornbeam, and pin oak.
[caption id="attachment_10301" align="aligncenter" width="763"] The forested restoration area was planted with a wide variety of native tree, herbaceous and shrub species. Shown here from top left: Canada Goldenrod, New England Aster and River Birch[/caption]  

EXPANDING THE PROJECT SCOPE

In addition to restoring the stream in the former impoundment, as a part of its Strategic Master Plan for Aquetong Spring Park, Solebury Township expanded its focus of the restoration project to include another 20 acres of forested land.

For this, Solebury developed a Woodland Restoration Plan which identified over 1,000 diseased forest trees, composed mostly of ash (Fraxinus sp.) and black walnut (Juglans nigra). It was the Township’s objective to remove the hazardous trees, re-establish a native woodland community, and establish an invasive species management program.

The trees removed as a part of this effort were repurposed for the stream restoration project and used for habitat features, stream stabilization measures, and park features (i.e. benches).

[caption id="attachment_10295" align="aligncenter" width="749"] Hazardous trees were removed and repurposed in the stream restoration construction, including the log grade control structures pictured here.[/caption]  

Princeton Hydro also provided stormwater design support for adjacent areas in Aquetong Spring Park, including multiple stormwater connections to the main tributary. After completion, Princeton Hydro provided bid assistance, developed a probable cost, drafted technical specifications, and produced a bid package to assist Aquetong Township in bringing the project to construction.

This restoration success could not have been possible without the hard work of so many dedicated project partners: Aquetong Spring Advisory Council, Bucks County Trout Unlimited, Solebury Township, Aquetong Township, Simone Collins Landscape Architects, PA Department of Conservation and Natural Resources, PA Department of Community and Economic Development, the National Fish and Wildlife Foundation, Lenni-Lenape Turtle Clan, and Princeton Hydro.

Princeton Hydro specializes in the planning, design, permitting, implementing, and maintenance of ecological rehabilitation projects. To learn more about our watershed restoration services, click here.  To learn about some of our award-winning restoration projects check out our blogs about the Pin Oak Forest Conservation Area freshwater wetland restoration project:

[visual-link-preview encoded="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"] [post_title] => Restoring Aquetong Creek: Stream Rehabilitation, Reforestation, and Invasive Species Control [post_excerpt] => [post_status] => publish [comment_status] => open [ping_status] => open [post_password] => [post_name] => aquetong-creek-restoration-project [to_ping] => [pinged] => [post_modified] => 2025-10-13 15:59:18 [post_modified_gmt] => 2025-10-13 15:59:18 [post_content_filtered] => [post_parent] => 0 [guid] => https://princetonhydro.com/?p=10290 [menu_order] => 0 [post_type] => post [post_mime_type] => [comment_count] => 0 [filter] => raw ) [comment_count] => 0 [current_comment] => -1 [found_posts] => 4 [max_num_pages] => 1 [max_num_comment_pages] => 0 [is_single] => [is_preview] => [is_page] => [is_archive] => 1 [is_date] => [is_year] => [is_month] => [is_day] => [is_time] => [is_author] => [is_category] => [is_tag] => 1 [is_tax] => [is_search] => [is_feed] => [is_comment_feed] => [is_trackback] => [is_home] => [is_privacy_policy] => [is_404] => [is_embed] => [is_paged] => [is_admin] => [is_attachment] => [is_singular] => [is_robots] => [is_favicon] => [is_posts_page] => [is_post_type_archive] => [query_vars_hash:WP_Query:private] => 26c74344f5b193a8d0d2b0b841983452 [query_vars_changed:WP_Query:private] => 1 [thumbnails_cached] => [allow_query_attachment_by_filename:protected] => [stopwords:WP_Query:private] => [compat_fields:WP_Query:private] => Array ( [0] => query_vars_hash [1] => query_vars_changed ) [compat_methods:WP_Query:private] => Array ( [0] => init_query_flags [1] => parse_tax_query ) [query_cache_key:WP_Query:private] => wp_query:42519d26734233bc2256c21295122c7d:0.46688600 17611702540.46561000 1761170254 )

Tag: habitat restoration

archive
 
Topics
Select Topics