The project is led by Kathy Boomer, watershed scientist for the Conservancy, and Amy Jacobs, watershed restoration director for The Nature Conservancy in Maryland/DC. They are working with scientists from the U.S. Geological Survey, the Natural Resources Conservation Service, U.S. Fish and Wildlife Service, and Maryland’s Department of Natural Resources to improve water quality and storage on the eastern shore of Maryland.
We sat down with Kathy and Amy to find out what this grant means for TNC and conservation in the Mid-Atlantic region.
"These sites can provide water quality and habitat benefits without significant loss to agricultural production."
What is the goal of the Conservation Innovation Grant?
Kathy & Amy:
The grant program is the Conservation Innovation Grant of the Natural Resources Conservation Service. It funds projects aimed at developing technology to assist with all aspects of farming, some of which help landowners, especially farmers, meet environmental and restoration goals. We’re using the grant to expand our floodplain restoration work on the Pocomoke River. Specifically, the three-year grant will provide an opportunity to work with our partners to evaluate water quality and habitat benefits provided by restored floodplains. Floodplain restoration provides a great opportunity for farmers to improve water quality, habitat, and other wetland services on their property without taking land out of production.
What will this grant money enable you to do?
Kathy & Amy:
This grant dovetails perfectly with our ongoing work in the Pocomoke River watershed to evaluate the benefits of targeted wetland restoration.
In agricultural regions across the country, we have severely altered how surface- and ground-water are delivered to our streams and rivers. On the Eastern Shore of the Chesapeake Bay, rural communities developed extensive ditch networks to drain vast areas of wetlands that historically occurred across the region, and to increase tillable land area. In addition, major streams were channelized to transmit water off the landscape and to the Chesapeake Bay as quickly as possible. Dredge spoil from the channelization was deposited next to the channel, thereby further isolating the Pocomoke River and its tributaries from adjacent floodplains.
The result is that when a lot of rain falls, the water rapidly moves through the river system. The “flashier” river system provides limited opportunity to sustain adjacent wetlands or benefit from the natural filter processes that floodplain wetlands provide. Prior to artificial channelization, the stream would overflow its banks onto floodplains, where natural processes removed sediment and nutrients from the water, and also provided water storage to prevent downstream flooding. Now that we understand the effects channelization has on the river ecosystem, there’s a lot of interest in reconnecting these natural floodplains.
This grant will provide us with a great opportunity to measure the water storage, water quality, and habitat benefits of floodplain reconnection. The information we collect will help us understand how the location and also design of the restoration project influences the benefits received from our investments and thus allow us to increase the effectiveness and efficiency of projects moving forward.
How do you reconnect floodplains?
Kathy & Amy:
When people channelized the stream, they straightened and deepened streams by digging out soil and piling it alongside the new channel. This spoil created a berm, which can function similar to a levee and prevents water from spilling over into the floodplains. To reconnect the floodplains, we excavate breaches in the spoil, varying from approximately 10 to 50 feet in width, down to floodplain ground level with very gentle slopes on either side of the breach. The number of breaches (or notches) depends primarily on the stream reach length. A plastic “geoweb” mesh is installed across the breach and backfilled with soil to stabilize the area and to allow for vehicles to continue accessing the area for channel maintenance. Once the area re-vegetates, the breaches often blend into the surrounding area.
What are the benefits to this wetland restoration?
Kathy & Amy:
During storm flow events, when water levels rise in the main channel, the constructed breaches will allow water to spill over into the floodplain. Removing water from the main channel can reduce downstream flooding and allows natural wetland filtering processes to occur.
One of the great things about wetland restoration is the wide range and number of benefits to humans and ecosystem. Floodplains provide a variety of services to people that we can enhance, including improved water quality, better wildlife habitat, more flood storage that will help with recent heavy flooding events in the area, and increased carbon storage.
Why are you excited about this project?
Kathy & Amy:
There are several exciting and important opportunities this grant will provide. First, there is a critical lack of information regarding how much sediment and nutrients are captured by floodplain wetlands. We know wetlands provide important water quality benefits we need, but we have a more limited understanding of how the location and design of a restoration might influence its capacity to provide these benefits. This grant will enable us to measure and compare how sites in different watershed positions provide the targeted water quality benefits. The grant will also enable us to evaluate habitat benefits, which TNC feels is an important benefit to wetland restoration. In short, the award is especially exciting because it will allow us to monitor the outcomes of restoration efforts. Until now, we have had great success with securing funds for restoration projects, but it has been more difficult to fund monitoring programs. We believe the support from the CIG program will provide critical information to help optimize our future investments in wetland restoration by providing a stronger, ‘smarter’ basis for identifying where we can achieve maximum water quality and habitat benefits.
We are also thrilled that the CIG award will enable us to engage scientists at USGS, NRCS, USFWS, and Maryland DNR in research that will provide direct benefits to our Chesapeake Bay restoration efforts. Our targeting approach has provided a great framework to develop collaborations with stakeholders, policy makers, and now the scientific community.
How do you monitor the performance of a floodplain?
Kathy & Amy:
Perhaps the major reason why there is such limited information about the capacity of wetlands to provide the ecosystem services we value is the difficulty of monitoring these dynamic systems that literally change with the weather. Working with floodplain ecologists from USGS and restoration scientists at NRCS, USFWS, and Maryland DNR, we will evaluate multiple approaches to floodplain monitoring. In addition to developing a better understanding of how much sediment and nutrients are captured in natural and restored floodplains, the three-year study will enable us to provide design recommendations for future monitoring programs.
Our baseline approach will include a network of continuous water-level monitoring stations across each of our study sites. We will use a combination of gauges to measure when and how much water flows into and out of these floodplains areas.
At the same time, we’ll measure sedimentation rates. We’ll place clay pads in the floodplain areas, next to our water level monitors, so we can see how much sediment falls out of the water on a seasonal basis.
We will also be looking at nutrient exchange, which is pretty high-level soil chemistry. We’ll study the soil to see how phosphorus is stored and what chemical conditions lead to increasing bioavailable. Phosphorus is usually found bound to sediment, so it’s not biologically available, but that form can change depending on water quality conditions. Because phosphorus is sensitive especially to water conditions in wetlands, it is important to determine whether floodplains act as long-term or short-term storage sinks.
The combination of data will help us evaluate what information is essential to understanding and estimating the benefits of these wetlands, so that future wetland monitoring projects can be more efficient and effective.
Where and when is this all happening?
Kathy & Amy:
We’re working in the Pocomoke River watershed, which occupies approximately 630 square miles of the larger Chesapeake Bay watershed (64,000 square miles). The Pocomoke River is in the lower Delmarva Peninsula, in the outer coastal plain, characterized by its extremely flat topography. The headwaters are in Delaware, and it flows down and enters the Chesapeake Bay in Virginia. There are more than 1,100 miles of ditches in the watershed.
Floodplain restoration is especially appealing because these sites can provide water quality and habitat benefits without significant loss to agricultural production. The restoration sites are primarily used for timber, hunting, and recreation. It’s one of those solutions that makes sense both ecologically and in the interest of keeping farmers farming.
The Nature Conservancy owns the largest natural preserve in the state, which includes the Nassawango Creek, a tributary to the Pocomoke River. The Nature Conservancy initially identified that as one of our focus areas because many rare plants and animals live in that watershed. This grant will help support our protection, and now our restoration efforts will continue to ensure those species and their habitats are protected and that both humans and ecosystems get cleaner water.