Using USC local delivery teams to facilitate wetland restoration in the Chemung and Susquehanna Basins
Contact: Jim Curatolo, Watershed Coordinator, Upper Susquehanna Coalition,
4729 State Route 414, Burdett, NY 14818, 607-546-2528, firstname.lastname@example.org
The Upper Susquehanna Coalition (USC) has developed a "Multiple Barrier Approach" (MBA) for planning and implementing restoration projects on a watershed basis. The MBA addresses the issue (such as flooding, streambank erosion, excessive sediment/gravel deposition or degraded fish habitat) at the source (e.g., headwaters), across the landscape, and in the stream corridor, as well as programmatically (e.g., regulations, training). By developing multiple projects to address problems, progress can continue and tangible results can be achieved even with smaller funding levels. This approach suggests planning, education, implementation and regulatory solutions to local stakeholders for their consideration. Multiple barriers can increase the probability of success and help capture stakeholder interest by demonstrating progress through implementation.
A successful Multiple Barrier Approach relies on a firm understanding of how each watershed functions in relation to its hydrological characteristics, drainage patterns, topography, land cover, land uses and misuses, precipitation events and other parameters. Flooding, streambank erosion, gravel deposition and nutrient loading are common problems in the USC Basin and priority USC issues. Wetland preservation, enhancement and construction are a key component of the MBA because of the wetland's capability to capture runoff, reduce runoff velocities and capture sediment.
Why Wetlands?A first consideration in watershed restoration planning efforts where flooding and streambank erosion are major issues should be an investigation of the potential for wetland construction and enhancement. Wetlands, especially in tributaries, tend to desynchronize flood peaks through their water holding capabilities as well as their vegetation that retards surface flow (Carter et al. 1978). Placement of wetlands in the upper reaches of a watershed will impede surface runoff and can reduce downstream erosion (Baker 1993). Novitzki (1985) found that watershed with four to five percent wetlands can have a 50 percent reduction in peak flood flows compared to a watershed that had none. Wetlands enhancement or construction should be considered early in watershed planning efforts in case they affect stream-flow characteristics and potential natural stream design projects.
There are few, if any, negative aspects to wetland development. Positioning wetlands to aid in water quality improvement and habitat enhancement, when those objectives are paramount, is still a fine example of the MBA as "flood attenuation is likely de facto" (De Laney 1995). Similarly, wetlands built primarily for flood attenuation will also have habitat benefits.
An "ideal" wetland from a flood attenuation point of view is one that would hold some amount of excess floodwater for a short period of time while not affecting the function of the wetland or its flora and fauna. The temporary water storage would reduce flood peaks and erosion downstream. Higher "freeboard" on dikes with a mechanism to return the wetland to a normal water level has great potential.
We are also interested in incorporating ephemeral or temporary wetlands into the mix. An example of this wetland type is the vernal pool, which usually is only flooded in spring and fall. It supports its own specialized fauna and flora due to the temporary nature of its existence. Ephemeral wetlands are easily disturbed and lost due to the very nature of how they function; when dry these wetlands may not even be recognized as such. Although they probably contribute relatively little to a watershed's water carrying capacity they may be one of the most important contributors to species diversity in wetland systems (Semlitsch and Bodie 1998).
We are also interested in the potential for incorporating ephemeral wetlands into a groundwater recharge project. In areas of high soil porosity, groundwater recharge may be substantial and help to attenuate floods by reducing surface flows as well as inhibiting drought by increasing the water table and augmenting stream base flow. If we could periodically flood a site with relatively flat topography, but with permeable, rather than hydric soils, we may develop pockets of standing water, which may develop into vernal pool type wetlands. The hypothesis is that vernal pools and other ephemeral wetlands would develop over time as these sites where sediments accumulated from the floodwaters that inundated them. We may want consider this option even if wetlands characteristics were established on only a very small portion of a site because of the groundwater and open space benefits that would result.
The overall goal of the USC Wetland Program is to develop a wide array of wetlands that meet the specific criteria of the funding programs, while attempting to integrate these designs into a plan that maximizes local benefits. Wetlands can be relatively quickly built compared to projects that require more data or funding and thus are an ideal "first project" to jumpstart local interest in a larger watershed restoration program.
The Local Delivery Team
Local delivery team. It is important that a local delivery team (LDT) is available to support wetland development, especially for such tasks as project planning and coordination, site selection, landowner contacts and such. The makeup of the team will vary, but most likely include Conservation District staff as well as county planning, local NRCS, watershed coordinators, watershed organization members and others. A team can address one or more projects, watersheds or counties. The LDT can implement the entire wetland development or enlist technical expertise for specific tasks. The following list include most tasks that a team and its technical partners must address during a typical wetland project:
1. Analysis of existing data to determine project watersheds
A review of existing information and strategic planning documents, especially WRAPS, would provide a short list of 11-digit Hydrological Unit Area (HUA) sized watershed where wetlands may be an implementation option to help reduce peak flood flows. Comparisons of the percent of existing wetlands in each subwatershed and their locations will also be helpful.
2. Site SelectionOverlaying hydric soils, orthophotos and topographic maps on a GIS to locate potential sites can be done in the office. This "computer survey" may save field time although it will also miss sites. Combining a computer survey with a field survey probably maximizes the chance to find all potential sites. The USC GIS Assessment Tool can be used for collecting field data on potential wetland sites and is a very good way to compile general site information and pictures for further discussion and SHPO request packages. A summary sheet of potentially useful information is provided at the end of this paper (see Wetland Project Site Information). Development of a "short list" of potential sites is essential for the LDT. College interns, with some training, can conduct the original field surveys; it will be used as the starting point for the technical partners to review, visit and determine which sites need to be pursued through the remaining tasks (tasks 6-12). Slope analysis (<1% and <3%) at the 14-digit HUA level can also provide additional information on wetland potential for a specific subwatershed.
3. Consider first or second order streams (wetlands in the headwaters)Wetlands in headwater areas capture water before it enters the stream channel, thus reducing the water's energy. Headwater areas, because of their locations and topography usually result in smaller sites being developed; building at multiple sites in the drainage can compensate for these size limitations. Smaller sites may be slightly more costly to build, but may have less construction and permit requirements because of their location and size.
4. Other site considerations
Building wetlands in watersheds that are high quality trout streams may be considered detrimental to the stream's temperature regime if the wetlands were a source of warmer water during events. This may be a rare occurrence as high quality trout streams, by their nature, are probably in relatively "good shape". One might consider attempting a groundwater recharge project to maintain base flow. Also the site selection process should include an overlay of regulated wetlands; work enhancing these might increase transaction costs compared to other, unregulated sites.
5. Install extra "freeboard" to temporarily capture runoff
If the funding agencies allow, an additional freeboard of reasonable height above the normal high water in the wetland as dictated by the water control structure could allow for dispensing additional water over a long enough time period to decrease flood peaks and help desynchronize flows between subwatersheds. Results of hydrological modeling in Seeley Creek show that many flows peak within 24 hours of an event; thus runoff need not be held for long periods, which might be detrimental to the integrity of the wetland.
6. Consider groundwater infiltration
An important practice that would enhance flood attenuation, and sustain stream base flows would be to augment groundwater through infiltration in areas of highly porous soils. At first this may seem counterintuitive to wetland development, which is always concentrated on hydric soils that by their nature are not conducive to such an procedure. However, ephemeral wetlands such as vernal pools many times occur on better-drained sites. One problem with development ephemeral wetlands is that many landowners may not value this type of wetland and not support its construction on their property. For those landowners who are providing sites without regard to the wetland type or for those few who may like the idea, development of ephemeral wetlands will aid in flood attenuation and also possibly aid in groundwater recharge to aid in drought relief. The USC plans to investigate the potential for recharging aquifers using groundwater recharge in areas of higher soil porosity, with a secondary potential benefit of forming ephemeral wetlands on portions of t he site that are or become conducive to holding water at least temporarily.
7. Meeting with landowners to discuss potential for wetland development
After the "long list" of potential sites is developed from computer and field work a meeting with landowners is in order to determine interest. The USC has compiled a series of fact sheets on wetland programs by agencies (these have been sent to Soil and Water Districts) that will help in describing the process. One consideration is to suggest some open water to entice residents to participate. Usually the case is that landowners want a pond and it is necessary to discuss the added value to wildlife of having wetlands along with open water, not to mention that funding is almost always tied to the wetland component. Attached is a discussion on West Nile Virus should the discussion turn to that potential problem.
8. Partner agencies/organization and their roles (in alphabetical order)
9. Accommodating partner requirements
Every funding agency has different criteria and a different philosophy behind its wetland program. We need to design the wetland that fits the site characteristics, landowner's wishes, local watershed objectives and the funding agencies requirements in order to be successful. With a flexible approach we may be able to maximize the number of sites and total wetland acreage in a watershed while taking into account these sometimes conflicting needs. The table ‘Agency/Organizational Criteria for Prioritizing Wetland Projects" provides a general summary of organization and agency goals; clarifications or changes top this table are greatly appreciated. The specific wetland requirements each organization requires to be involved in a project must be investigated on a project-by-project basis.
Wetland Project Site Information
Site name/number: ____________________________________________________________
Owner's name, address, & phone no.: _________________________________________
Latitude: _________________ Longitude: _________________
Description of proposed project: ___________________________________________________
Type of wetland: _____________________________________________________________
Estimated construction cost: $_______________ Cost of land/easement: $_______________
Property owner funding? ___________ Land donation? __________ Easement? __________
Maintenance & long-term protection: __________________________________________
Sub-watershed: __________________________ Wetland creation priority: ______________
Size of potential wetland: _____ acres Watershed location/stream order: ______
Water source: ___________________________ Drainage area: ________ acres
Soil types: __________________________________________ Hydric soil? ____ acres
Existing wetland? ____Yes ____No If yes, wetland type: _______________________
Surrounding land use(s)/vegetation type(s): __________________________________
Landowner objectives/requirements: ___________________________________________
Potential to reduce streambank erosion: ______________________________________
Flood attenuation benefits: __________________________________________________
On-site habitat enhancement: _________________________________________________
Part of a larger natural area or corridor? ___________________________________
Groundwater recharge potential: ______________________________________________
Water quality benefits: ______________________________________________________
Public access? ____Yes ____No Public visibility: ___________________________
Agency/Organizational Criteria for Prioritizing Wetland Projects
Wetlands serve many functions, which are valued differently by the various agencies and organizations interested in their preservation and restoration. The following table describes the project criteria that are most important to various agency partners.
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