Delaware Wetlands logo
WMAP Blog


Delaware Wetland Monitoring & Assessment Program


Facebook  Twitter  Instagram  Pinterest  YouTube  RSS Feed

  Archived Posts From: 2017

wetland-assessments

Tidal Freshwater Wetlands

Written on: September 19th, 2017 in Wetland Assessments

You may already be aware that saltwater wetlands are influenced by ocean tides, and that freshwater wetlands located further inland are not influenced by tides.

But, did you know that there are freshwater wetlands that are actually still influenced by the ocean’s tides?

These wetlands, commonly called tidal freshwater wetlands, are in some ways similar to other wetland types. For example, tidal freshwater wetlands provide many of the same services that other wetland types provide, including floodwater storage, improvements to water quality, and wildlife habitat.

Tidal freshwater wetlands also experience some of the same problems that other wetland types experience, including the presence of invasive species like the common reed (Phragmites australis), and the presence of development or agriculture in the area surrounding the wetland.

However, tidal freshwater wetlands are also different in many ways from other wetland types. Though not an all-inclusive list, here are two big ways that tidal freshwater wetlands differ from their other wetland counterparts:

  1. Landscape: Part of what makes tidal freshwater wetlands different is their location in the landscape. These wetlands are located just far enough away from the ocean where salinity (i.e., how salty the water is) is extremely low, and freshwater flows into these wetlands from headwaters further upstream. Yet, these wetlands are still just close enough to the ocean to experience high and low tides. Other wetland types are either located closer to the ocean and are therefore saltier or are even further inland and do not experience tides.

    Freshwater tidal wetland location verses saltwater tidal wetland location

    Shown above is an aerial view of the Leipsic River in Kent County, Delaware. Circled in red on the left is an example of an area with tidal freshwater wetlands, and circled in red on the right is an example of an area with saltwater tidal wetlands. Notice that the freshwater tidal wetlands are further upstream (i.e., further from the Delaware Bay, inland) than saltwater wetlands.

  2. This flowering plant is pickerelweed (Pontedaria cordata), a common plant found in both non-tidal and tidal freshwater wetlands but not in salt marshes.

    Plant Community: Tidal freshwater wetlands tend to have a lot of the same plant species as non-tidal freshwater wetlands, such as arrow arum (Peltandra virginica), annual wild rice (Zizania aquatica), big cordgrass (Spartina cynosuroides), water smartweed (Polygonum punctatum), pickerelweed (Pontedaria cordata), broadleaf arrowhead (Sagittaria latifolia) and spatterdock (Nuphar species); however, these plant communities differ greatly from those found in salt marshes. Smooth cordgrass (Spartina alterniflora) or saltmeadow cordgrass (Spartina patens) commonly dominates salt marsh communities, whereas they are often completely absent in tidal freshwater wetlands. Additionally, tidal freshwater wetlands usually have much more plant diversity than salt marshes, meaning that there tends to be a higher number of species present in tidal freshwater wetlands compared with salt marshes.

    These two pictures show the contrast between common plant communities in Right: A salt marsh (Leipsic River watershed, summer 2013), and Left: A tidal freshwater marsh (Red Lion watershed, summer 2017).

Now that you know a little bit about these wetlands, your next question might be: do we, WMAP, assess the condition of tidal freshwater wetlands in Delaware? Our answer: Yes!

Throughout this summer (2017), we have been assessing wetlands in the Red Lion watershed in New Castle County. Many of our tidal wetland sites thus far have been freshwater tidal wetlands. We can determine if a site is a freshwater or saltwater tidal wetland by measuring the salinity of the water, looking at the plant community, and looking at its position in the landscape using aerial photos.

To learn more about other wetland types that we have in Delaware, visit the Delaware Wetlands website and our blog post about Delaware’s Unique Wetlands.


Tags: ,

wetland-animals

Delaware’s Crayfish

Written on: September 19th, 2017 in Wetland Animals

Did you know that Delaware has multiple species of crayfish? While crayfish may look like small lobsters, they are actually distant cousins. The most differentiating feature is that lobsters live in saltwater, and crayfish, crawfish, crawdads, or whatever you would like to call them, live in fresh to brackish waters.

This crayfish chimney is the entrance to the crayfish’s underground tunnels. Depending on the species, there may be multiple chimneys or entrances.

Some crayfish species living in Delaware are naturally occurring here (native), while some come from other parts of the country (invasive), and they all come in various colors and sizes. You are likely to find these crustaceans in flowing streams, lakes, swamps, ponds, and seasonally wet wetland habitats. They live their lives safely burrowed in underground tunnels or hiding out in open water, or some combination of the two. Fun fact, as long as the crayfish’s gills stay moist, it can breathe on land or in the water.

Crayfish are opportunistic feeders using the two antenna on the top of their head to seek out the chemicals that “smell” most tasty to them. They will chow down on decomposing plant or animal parts, slow moving macroinvertebrates such as snails, underwater grasses, amphibians, and fish eggs. Interestingly enough though, juvenile crayfish seem to prefer a diet consisting of mostly meat, while adult crayfish seem content munching away on plant materials.

On the other hand, crayfish also serve as a tasty treat to bass, snapping turtles, raccoons, and herons, and are used as bait by fisherman to catch fish.

The white river crayfish (Procambarus acutus) is one of a few species that is native to Delaware. They can range in color from pinkish tan to brownish olive and have a broad dark stripe along the abdomen.  The claws are slender and have small dark spots. This particular little guy was found dead.

These hard-shelled critters also have interesting behaviors. To escape a predator, they will try to tail flip themselves away. Don’t think they are wimps though, because they aren’t afraid to get down and dirty. Fighting is commonplace among crayfish, whether it be over food, shelter, or selecting the perfect mate. They box, push, grasp, and grab at their opponent until one submits or loses a limb.

But, how does one crayfish know when the other has submitted? Crayfish have developed body language and chemical signals that let their opponent know when they’ve given up. If a crayfish lays its body flat against the ground with its claws forward, or if it does a tail flip and propels itself backwards, it has submitted and the battle is over.

This invasive species of crayfish, the red swamp crayfish (Procambarus clarkii), is found in Delaware.

Crayfish behaviors can vary by species, especially when it comes down to aggression. For example, the red swamp crayfish (Procambarus clarkii) is known for its very aggressive behavior and delicious taste, and it just so happens to be an invasive species right here in Delaware. It uses its aggressive behavior to out-compete native species of crayfish and amphibians for shelter and food.

Native to the U.S.’s Gulf Coast, the red swamp crayfish made its way to Delaware through people releasing or disposing them as unwanted food, pets, or bait. One paper from Indiana hypothesized that flushing crayfish down the toilet was an inappropriate way to dispose of them because they were being found around waste water treatment facilities, “having apparently survived treatment.”

Long story short, crayfish are cool, but the invasive species are bad, and never flush unwanted animals—including crayfish– down the toilet because you never know where they might end up (or what they might turn into).

Red Swamp Crayfish Identification:
• Tolerates a range of salinities and pollution
• Can grow up to 5 inches long
• Dark red in color
• Raised bright red spots on claws and body
• Juveniles are not red and can be difficult to identify
• Have an approximate two year life span in the wild
• If you see one, please report it to the Delaware Division of Fish and Wildlife at 302-735-8655 or 302-735-8652

Resources:
Gherardi, Francesca, and William H. Daniels. “Agonism and shelter competition between invasive and indigenous crayfish species.” NRC Canada, 24 Feb. 2005, pp. 1923–1932.

Jurcak, Ana M, et al. “Behavior of Crayfish.” Biology and Ecology of Crayfish.

“Red Swamp Crayfish (Procambarus Clarkii) Ecological Risk Screening Summary.” U.S. Fish and Wildlife Service, Feb. 2011.


Tags: ,

wetland-assessments

Blue Carbon – a benefit to protecting tidal wetlands

Written on: September 19th, 2017 in Wetland Assessments

Guest Writer: Kari St.Laurent, Delaware National Estuarine Research Reserve

Wetlands are more than just a beautiful photo opportunity. If you are a reader of this blog, you are probably aware that tidal wetlands can protect shorelines from storm surge, reduce nutrients, and provide habitat for critters like shellfish, crabs, and fish. These benefits are collectively known as ecosystem services. Recently, there is another ecosystem service that has been gaining interest from wetland scientists, coastal resources managers, and policy-makers alike – the ability for tidal wetlands to trap and store carbon!

Marsh sediment core

A shallow marsh sediment core from the St. Jones Reserve displays over a foot of carbon-rich marsh sediment.

Tidal wetlands can store mass amounts of carbon within its thick layers of sediment. Plants, including Spartina alterinflora, take in atmospheric carbon dioxide during photosynthesis and turn it into part of their cellular structure. When these marsh plants die, that carbon can be buried into the marsh sediment where it can stay trapped as organic matter for millennia. Organic matter can also be deposited onto a marsh by tides and water coming off from land. This process of carbon going from the atmosphere into marsh plants and sediments is called carbon sequestration.

One key feature of a tidal marsh is its ability to accrete, or be able to vertically build-up sediment to keep pace with local sea level changes. As this layer of marsh sediment gets deeper and deeper, it becomes harder for this trapped carbon to get released back into the atmosphere. Thus, marshes can be a sink for carbon dioxide!

This storage of carbon within tidal wetland ecosystems has earned the name blue carbon. Impressively, tidal wetlands can store more carbon per area than a forest because of its deep layers of mud – measured as deep as 32 feet in Belize. And that carbon in a tidal wetland can be stored for 1000’s of years while systems like a rainforest store carbon for shorter periods, such as decades to centuries. This makes blue carbon an important component of the global carbon cycle.

Delaware wetlands map

Approximately 23% of Delaware’s wetlands are emergent estuarine, which equates to about 73,000 acres.

Healthy marshes will continue to trap and store carbon, in addition to providing valuable habitat, protection from storms, and natural filtration of nutrients. However, when marshes are lost or degraded, that carbon storage benefit is lost – and even more, that previously stored carbon can be released back into the environment. The protection and restoration of wetlands is a great way to help continue carbon sequestration and storage within tidal wetlands.

So just how much carbon is sequestered each year within Delaware’s approximately 73,000 acres of tidal wetlands? This past summer, DNREC-Delaware Coastal Programs hosted Bryce Stevenosky, a DENIN intern from the University of Delaware, to help us understand this question using published scientific literature. While this is just a back-of-the-envelope type of estimate, it starts to put the amount of blue carbon into perspective for Delaware’s wetland scientists.

Bryce estimated the amount of carbon sequestered each year into Delaware’s marsh sediments is 57,000 metric tons of carbon dioxide. To put this into perspective, the average car emits 4.7 metric tons of carbon each year. This means that Delaware’s wetlands sequester the emissions of over 12,000 cars each year. That’s greater than the population of Smyrna!

This estimate is just the beginning for Delaware’s coastal resources managers and scientists to understand the role wetlands play in storing carbon dioxide, and what we could stand to lose if wetlands are lost. More work needs to be done in Delaware to understand these complex processes and put a site-by-site specific value on just how much carbon Delaware’s tidal wetlands are trapping for us.


Tags: , ,

wetland-restorations

NVF-Yorklyn Cleanup and Redevelopment – an unprecedented partnership

Written on: September 13th, 2017 in Wetland Restorations

Guest Writer: John G. Cargill, IV, DNREC Division of Watershed Stewardship/Division of Waste and Hazardous Substances

Demolition of buildings at the NVF Yorklyn Site

Demolition of buildings at the NVF Yorklyn Site

The National Vulcanized Fiber (NVF) plant located in Yorklyn, Delaware has a rich history with humble beginnings in grist, snuff, lumber, and cotton. By the mid 1800s, production in the valley shifted to paper, and by the early 1900s shifted again to vulcanized fibre. Due to the early success of fibre production, the local Marshall Brothers Company expanded into the National Fibre and Insulation Company and later into the NVF Company. Operations at NVF between 1960 and 2003 were busy. The main mills and the Marshall Brothers Mill were operated 24 hours a day, 7 days a week, moving approximately 40-41 million pounds of material annually. Eventually demand and production slowed, and by 2008 the staffing and traffic of the mills had reduced to about ¼ of the totals from the height of the company. By 2009, the NVF Company had declared bankruptcy and shut down the facility for good.

At the same time that NVF operations were winding down, the Department of Natural Resources and Environmental Control’s (DNREC) Division of Parks and Recreation (Parks) was acquiring land in and around the valley. By the end of 2008, Parks was managing 192 acres of valuable conservation and cultural resource lands known as Auburn Heights Preserve (which also includes the original Marshall family mansion and its steam car museum) and another 121 acres known as the Oversee Farm. Between the two areas of conservation land, and adjacent to the Red Clay Creek, was the former NVF Company plant. Here’s where things get interesting…

Concerns and interest in the NVF properties were far reaching. DNREC’s Division of Waste & Hazardous substances was concerned about hazardous materials and unknown environmental issues; DNREC’s Division of Water Resources was concerned about known impacts to aquatic life in the Red Clay Creek from plant operations; DNREC’s Division of Soil and Water Conservation was focused on historic flooding problems and the hazards posed by an abandoned facility in the flood plain; DNREC’s Division of Parks and Recreation saw an opportunity to connect its other properties in the valley; private investors were interested in the redevelopment potential of creek-side property; and the surrounding community was concerned about all of it. So now what ?

Working as a unit, DNREC put together a multi-divisional working group that began to secure the site and gather information about environmental conditions at the site. DNREC Parks worked with a private investment group to acquire the 119 acres of NVF Company land from the Bankruptcy Trustee, and soon after negotiated rights to various parcels for future Park related development and connection of existing Park amenities. Through this unique partnership, DNREC assumed responsibility for the assessment and environmental cleanup of the former plant properties, while the private developer took responsibility for all asbestos abatement and demolition of existing unwanted structures.

Created wetland at the NVF Yorklyn Site

Created wetland at the NVF Yorklyn Site

Fast forward to August 2017. All of the structures that will not be redeveloped have been demolished. The feasibility study conducted to determine the best cleanup options for contaminated portions of the property has been, more or less, implemented and completed. Aside from the continuously operating groundwater remediation system that keeps dissolved zinc in groundwater from entering the Red Clay Creek, the most aggressive and costly portion of site remediation entailed zinc source removal (from soil) and creation of a 2-acre wetland to serve as flood water storage capacity.

During the excavation project, over 170 tons (340,000 pounds) of zinc was removed from the soil beneath the former manufacturing facility. In addition, between 500 and 700 pounds of zinc are recovered monthly from the groundwater through the operation of the treatment system.

The majority of non-permeable surfaces have been removed from the site to foster better drainage, and more wetland projects are planned on DNREC owned properties in the valley for additional flood water storage capacity. Finally, pervious paving materials will be used in all roads and parking lots associated with future site redevelopment.

Hazardous Substance Cleanup Act (HSCA) funds have supported approximately $4.5M of the assessment and cleanup efforts, with another $3M on loan from the Clean Water Loan Fund for the zinc source removal/floor mitigation wetland project. Additional State funding is provided to DNREC Parks for ongoing development of trails and other area amenities. At this point in time, the former plant site is ready for additional development, both commercial and/or residential.

Moving forward, the Wilmington and Western Railroad steam train will continue to run through the valley as it always has, but a new turntable and a train station will be added to the former NVF Company property to improve public access to services and amenities. Miles of hiking trail will be accessible from this centralized location, including three historic bridges that will cross the Red Clay Creek within the valley.

Concept drawing of Yorklyn Village

Concept drawing of Yorklyn Village

An outdoor amphitheater is planned to serve the Delaware Symphony Orchestra as their summer concert home, and residential redevelopment is being planned for one of the former mill building sites (including a stream restoration project along Yorklyn Road).

Public water and sewer are currently being extended to the site to support these and other amenities, including restaurants and shops, that will inevitably follow as the realization of this unprecedented partnership between public and private entities for renewal and revitalization of the Auburn Heights/Yorklyn Valley area are realized.


Tags: , ,

beneficial-use

Beneficial Reuse of Dredge Material on a Tidal Marsh

Written on: May 24th, 2017 in Beneficial Use

Dredge definitionWhat is one way to give a marsh a lift with the challenge of rising seas? Spray the muddy material that has been dredged up from the bottom of a creek in a thin layer on top of the marsh. But how much mud is too much, and can the plants survive? These are a couple of the questions we (Wetland Monitoring & Assessment Program) set out to answer.

In 2013, Pepper Creek in Dagsboro was set to be dredged, so we rallied the troops and came up with a plan to test out how the beneficial reuse of dredge materials (also called thin layer application) affect marshes in Delaware. The resulting spoils from dredging were thinly sprayed over the marsh at the Piney Point Tract of the Assawoman Wildlife Area, and long term monitoring stations were set up.

Dredge material being sprayed on marsh surface.

Dredge material being sprayed on marsh surface.

For the past three years we have been looking at how the plant community has responded to the application, and how the marsh surface has changed by performing Real Time Kinematic (RTK) GPS transect surveys of the area and measuring surface accretion with feldspar marker horizon plots.

From the data we have been gathering we’ve figured out a couple of things that work and some things that need further study for future projects:

feldspar plot in application area

Feldspar assessment plot in a thin layer dredge application area.

So the nitty gritty of it is that spraying dredge materials on top of a marsh can increase the height of that marsh. But, careful attention must be paid to how thickly the mud is sprayed, and the site should be monitored for problem areas that need replanting.

This project was done in partnership with DNREC’s Shoreline and Waterway Management Section.  For more information or questions about this project, please contact Alison Rogerson at alison.rogerson@state.de.us or 302-739-9939.


Tags: , , , , ,

wetland-assessments

Keeping an Eye on the Rising Tide: SSIM

Written on: May 24th, 2017 in Wetland Assessments

Coastal wetlands are a hallmark feature of the Delaware’s Bayshore, making up about 23% of all wetland types in the state. Because of the many beneficial services these wetlands provide, such as wave energy reduction, the survival of coastal wetlands is an important part of protecting our seaside communities from threats associated with the changing climate.

SSIM Feldspar Monitoring

Measuring the amount of sediment on top of a feldspar (a type of clay) marker for a SSIM site.

We here at DNREC’s Wetland Monitoring & Assessment Program (WMAP) are doing our part to track changes in coastal marshes with the long-term monitoring of fixed sites in the Christina and Broadkill watersheds.

To do this, we’ve joined in on the Mid-Atlantic Coastal Wetland Assessment (MACWA) method by maintaining Site Specific Intensive Monitoring sites, also called SSIM (pronounced sim). This monitoring effort establishes fixed stations in coastal marshes and looks at a couple of different factors including water quality, soil quality, plant community, and marsh surface characteristics to help determine if that marsh is capable of keeping up with sea level rise.

walking-out-to-ssim-site

Scientists from WMAP and PDE walking out to SSIM field site to begin monitoring efforts.

There are currently seven fully established SSIM stations in the Delaware Bay Estuary network with two of them residing right here in the little state we call home, Delaware. Two or three times a year, three to four scientists (or scientists in training) slide on their hip boots, head out to the marshes and gather data.

The first SSIM site was installed in Delaware in 2010 on the Christina River in the Russell Peterson Urban Wildlife Refuge. This site is a freshwater site that is impacted by both the past and current chemical industry and from marsh fragmentation caused by the construction of highways in the 1960’s.

The second site in Delaware is located in the Great Marsh Preserve along Canary Creek, an offshoot of the Broadkill River, in Lewes and was installed in 2014. This station is the most downstream location out of the seven in the Delaware Bay Estuary and has the saltiest water of all of the sites because of its proximity to the Atlantic Ocean. The surrounding landscape of this area is agricultural, with some housing communities. Like most salt marshes along the east coast, these areas were historically ditched for mosquito population control.

With each passing year we gather more and more data at these two SSIM sites that will help us understand more about our marshes’ ability to keep up with sea level rise. Be on the lookout for future updates about this project!

This project is done in partnership with the Partnership for the Delaware Estuary (PDE).


Tags: , , , ,

uncategorized

Floating Wetlands

Written on: May 24th, 2017 in Outreach

Guest Writer: Phil Miller, DNREC’s Nonpoint Source Program
YCC preparing to install floating wetlands

The Delaware Youth Conservation Corps preparing to install floating wetlands at Trap Pond State Park.

We’ve all heard about wetlands before but have you ever heard of a floating wetland?

Floating wetlands are artificial islands with plants on top and roots below. Similar to a natural wetland, they improve water quality by soaking up nutrients, such as nitrogen and phosphorus. These two nutrients are the primary causes of algal blooms, which make it difficult for fish and other aquatic life to survive.

Every time it rains, pollutants from lawns, roads, and other surfaces are swept into our waterways. Fortunately, we’re able to battle this runoff with floating wetlands, an efficient tool for cleaning polluted water. As the plants of the wetlands grow, they remove nutrient pollution and store it in their leaves while adding life-giving oxygen to the water. At the same time, their roots provide a home for microorganisms that feed on pollution.

The only element needed for all this to work? Simple sunlight.

Floating Wetland End of Season 2

Floating wetland in the fall of season 2.

In 2015 DNREC purchased twelve floating rafts and native plants which were then linked together to form two groups of floating wetlands. The Delaware Youth Conservation Corps installed the two wetlands at Trap Pond during the Nanticoke Watershed Alliance’s annual Wade In and Nanticoke River Report Card Release event. Since then, it’s been a huge hit, not only for the students who got to install them, but also for everyone else at the park that couldn’t wait to hop in a kayak and paddle out to see them.

Over the past couple years, the wetlands have flourished and have been a destination point not only for curious paddlers but also for fisherman hoping to catch one of the many fish that find habitat in the cooler cleaner water below the raft’s root system.

Luckily, the geese have not been interested in joining in the fun. If that had occurred, there were certain plants that would have been added to deter them as well as other techniques that would have been put in place but proved not to be necessary. The turtles on the other hand, call it home –finding food and a place to sunbathe.

Floating Wetland Spring of Season 3

Floating wetland in the spring of season 3.

Due to the huge size of the pond, water quality improvement was not the intention of this project. This is simply a demonstration project that provides an opportunity for people to see what they are and learn about how they work.

Trap Pond is an ideal setting, not only because of the traffic through the park –the fisherman, paddlers, boaters, hikers, campers, students and anyone who passes them, but also because of the accessibility. To be able to paddle out and get a close up look at exactly how it’s working has been enjoyed and appreciated by the park’s visitors since the day they were installed. They’ve since been added as an educational component of the pontoon tours and canoe and kayak trips.

Stop by Trap Pond to see their progress this summer!


Tags: , , ,

wetland-restorations

Re-Engineering Nature in Delaware Tax Ditches

Written on: May 22nd, 2017 in Wetland Restorations

Guest Writer: Melissa Hubert, DNREC’s Drainage Program

Fun fact, did you know that there are 234 tax ditch organizations scattered across Delaware that provide water management services to over 100,000 residents and nearly half of the state-maintained roads?

These watershed based organizations are responsible for maintaining over 2,000 miles of ditch channel to ensure the drainage functionality of these systems stays running strong. This is no easy feat considering most tax ditches were constructed over 30 years ago when the landscape across Delaware looked much different. The aging infrastructure of most tax ditches in conjunction with landuse changes have resulted in major maintenance concerns that need to be addressed.

Conditions of the Bridgeville Branch Tax Ditch channel before the stream restoration project. Note the straight channel.

Conditions of the Bridgeville Branch Tax Ditch channel before the stream restoration project. Note the straight channel.

As these engineered systems attempt to handle stormwater flows that they were not designed for, the ditch channels often undergo changes caused by moving water that deepen and widen the channels, cause bank erosion, and create sediment bars. These side-effects change the ditch systems from their original designs which in turn, may limit their water capacity, decrease response time to storm events, and make it more difficult to perform channel maintenance.

Bridgeville Branch Tax Ditch channel after the stream restoration project was completed. Note the meander of the channel, which is similar to the flow of natural streams

Bridgeville Branch Tax Ditch channel after the stream restoration project was completed. Note the meander of the channel, which is similar to the flow of natural streams

The DNREC Drainage Program is working with tax ditch organizations to determine ways to mimic natural in-stream processes and features with the goal of minimizing maintenance needs while still enhancing the ability of these systems to transport and clean water.

Here’s an example of one of those projects:

A portion of the Bridgeville Branch Tax Ditch, located in the Town of Bridgeville, was undercutting and widening to the point that both a sanitary sewer and water line were exposed within the channel. For a permanent solution to this serious issue, the exposed lines were properly encased and a channel that mimics a natural stream was constructed to further protect and enhance the project area.

Soil lifts with live branch cutings placed between each layer to protect this bend where the sanitary sewer line is located and improve in-stream habitat.

Soil lifts with live branch cutings placed between each layer to protect this bend where the sanitary sewer line is located and improve in-stream habitat.

Natural streams transport water through the path of least resistance and as a result, many twists and turns tend to develop as water moves. For this project the ditch channel was re-aligned to establish a meandering flow path with adjacent floodplain benches to reduce the energy moving through the channel during normal and higher storm flow conditions.

In addition a stilling basin was constructed just downstream of four large pipes to slow the water when it entered the project area. A series of riffle and pool structures were created to provide flow diversity within the channel. These features not only reduce future maintenance needs, but capture and prevent pollutants from being transported further downstream, and create spawning habitat for all those critters we love.

The live branch cuttings really taking off providing bank stabilization, wildlife cover, and shade for the channel.

The live branch cuttings really taking off providing bank stabilization, wildlife cover, and shade for the channel.

Tree logs and root wads were pushed into the banks to provide natural protection from erosion as well as wildlife habitat and cover. Soil lifts or soils wrapped in an organic material were installed with branches placed between each lift to restore a portion of the ditch bank that was previously lost to erosion.

Last but not least the entire project area was planted with native species of riparian grasses, trees, and shrubs with live branch cuttings planted on the banks to rapidly establish stability, shade, and in-stream cover.

In this project nature was re-engineered by implementing natural design techniques and features that not only improved the functionality of the tax ditch channel and reduced future maintenance needs but also enhanced wildlife habitat and water quality.

It is the DNREC Drainage Program’s hope to help tax ditch organizations plan and construct stream restoration projects like this one to address maintenance issues in the future.

Delaware Tax Ditch Map

Visit this site to see where tax ditches are located near you.

Interested in getting involved? Tax ditch meetings are held annually, organized by watershed, to voice maintenance concerns and other topics. Any decisions are voted on by property owners within their own tax ditch watershed. With the prevalence of tax ditch organizations across Delaware you may even live in a watershed that has one. Check out this app to find out.


Tags: , , ,

living-shorelines

Shoreline Stabilization Solutions for You!

Written on: May 22nd, 2017 in Living Shorelines

Where to Begin and an Expedited Permitting Process.

Guest Writers: Julie Molina, Katie Huegel and Matt Jones of DNREC’s Wetlands & Subaqueous Lands Section

Armored Living Shoreline

Pictured above is an armored living shoreline used in a high energy area. The project stabilized 150 linear feet of shoreline using a marsh toe sill with coir fiber logs and wetland vegetation planted behind the sill.

Delaware’s coastal communities face constant challenges from shoreline erosion. Historically, tidal wetlands act as the natural solution for shoreline stabilization. Tidal wetlands provide protection against shoreline erosion, a mechanism for flood control and natural habitat for many plant and animal species. Coastal communities today can still take advantage of having a natural means to stabilize their shorelines!

Having a natural, “living” shoreline is an increasingly popular option that provides a variety of ecological benefits while also serving a homeowner’s main goal of erosion control. For those with an interest in fishing and crabbing, the regaining of this critical riparian habitat has been proven to almost double the densities of these creatures when compared to bulkhead or riprap.

So what’s the next step?

Lewes Living Shoreline

Pictured above is a non-structural living shoreline in a low energy area. The project stabilized 84 linear feet of shoreline using coir fiber logs and wetland vegetation.

There are many different designs used when installing a living shoreline. From using coir fiber logs, to oyster castles, to a marsh toe sill with wetland plantings – the possibilities are endless. Since every shoreline is different, a site-specific design is required for successful results. Getting in contact with a consultant or contractor in order to determine which type of living shoreline would work for your property is an important next step. You can reach a consultant or contractor specializing in vegetative shoreline stabilization techniques here.

The Wetlands and Subaqueous Lands Section at DNREC has an expedited permitting process to authorize the construction of these natural living shorelines.

As long as the project meets the parameters outlined here, the Statewide Activity Approval for Shoreline Stabilization Projects can be used by coastal community residents to naturally protect their shoreline. For more information on natural living shorelines, please contact our office at (302) 739-9943.


Tags: , , , ,

wetland-restorations

Making the Great Cypress Swamp Great Again

Written on: March 16th, 2017 in Wetland Restorations

Guest Writer: Andrew Martin, Field Ecologist, Delaware Wild Lands

The Great Cypress Swamp once covered nearly 60,000 acres. Although a long history of ditching and draining for agriculture and development has reduced its vast expanse, the Swamp remains Delmarva Peninsula’s largest contiguous forest and largest freshwater wetland.

Freshwater wetland in Sussex County, DE.

Freshwater wetland in Sussex County, DE. Credit: Andrew Martin, PASM Photography

For the last 50 years, Delaware Wild Lands (DWL) has been strategically purchasing and restoring this delicate ecosystem. The first parcel that DWL ever acquired was Trussom Pond in 1961. This purchase launched our efforts to protect Delaware’s iconic cypress swamp habitat. Today, DWL owns and manages more than 10,5000 contiguous acres of the Great Cypress Swamp in Sussex County and overlapping the state line into Maryland.

Trussum Pond and the 1,200 acres of unique wetlands associated with it, were handed over to the Delaware State Parks system in 1991, but our commitment to the private protection of wetlands continues. Today, as Delaware’s largest non-profit non-governmental landholder, DWL owns more than 21,000 acres throughout Delaware, and we’re actively engaged in wetland restoration in all three counties.

The Great Cypress Swamp is home to our largest and most ambitious wetland restoration work. It also contains the headwaters of the Pocomoke River, an important tributary to the Chesapeake Bay. In 2011, we installed a series of water control structures in the historic ditches, allowing us to hold back millions of gallons of water that otherwise would have drained away. In only six years, we have rehydrated hundreds, if not thousands of acres of the Swamp.

Our wetland restoration in the Great Cypress Swamp began, perhaps surprisingly, with a 150-acre timber harvest. At the time, this area was a dry woodland. Harvesting timber helped us prepare the site as we began redirecting water and creating a restored emergent wetland. The revenues from timber sales are reinvested back into restoration expenses.

Planting seedling trees.

Planting seedling trees. Credit: Andrew Martin, PASM Photography

Since 2011 we’ve planted 173,000 native trees – a few thousand Baldcypress seedlings throughout, and tens of thousands of Atlantic White-cedar planted in the transitional and upland areas. Later this spring, we’re planning to plant 21,000 more trees.

As ecological systems are restored in the Swamp, a rich diversity of animal species is also returning. Each spring, hundreds of acres of newly-flooded woodlands echo with the “clack-clack-clack” of Carpenter Frogs and the mating calls of other species of frog. In some places, mature trees are dying in standing water, providing habitat for Red-headed Woodpeckers, Wood Ducks, owls, and other cavity nesters.

Spotted turtle. Credit: Andrew Martin

Spotted turtle. Credit: Andrew Martin, PASM Photography

Spotted Turtles – named by the Endangered Species Coalition as one of the top ten species most threatened by habitat fragmentation – now have hundreds of new acres to spread out and spawn. A new abundance of seed from wetland grasses, aquatic insects, amphibians, and even fish now provide food for wading birds like herons and egrets, and waterfowl like Mallards and Black Ducks. It is not uncommon to see dozens of Bald Eagles and other raptors soaring overhead.

Because of its delicate and sensitive nature, the Great Cypress Swamp – like all Delaware Wild Lands properties – is not open to unscheduled visitation. We do, however, offer guided tours. And the next opportunity for the public to visit the Swamp is even more fun than usual! Come join us on Saturday, May 20 for some great music at our annual Baldcypress Bluegrass Festival.

We’ll have five foot stompin’ bands playing all day from 12-6PM on a stage that backs right up to 150-year-old Baldcypress trees. Craft beers and wines will be flowing and several food trucks will be serving a delicious menu. New this year is a craft vendor area with members of the Dewey Artist Collaboration and DNREC’s Mobile Science Lab with interactive exhibits about the Chesapeake Bay Watershed.

Tickets to the festival include free bus tours through the Great Cypress Swamp that will pass right by our massive wetland restoration sites. Tickets are only $25 in advance or $35 at the gate. All proceeds benefit Delaware Wild Lands. Visit www.dewildlands.org  or http://facebook.com/DelawareWildLands/events  for more information and tickets.


Tags: , , ,

Delaware Wetland Management & Assessment Program
+