Wetland Mitigation and Restoration

What are the 4 regulatory basis for wetland mitigation?

1. Section 10, Rivers and Harbors Act 2. Section 404 Clean Water Act 3. "No net loss" federal guidance 4. State regulations

What is the success rate of wetland creation

10-25% success in terms of function and values

What is the 3 step mitigation sequence? And how did this come about?

1990 agreement between EPA and Army Corps of Engineers Step 1. Avoid- adverse impacts to aquatic resources are to be avoided an no discharge shall be permitted if there is a alternative with less impact Step 2. Minimize- if impact cannot be avoided, practices to minimize impacts must be taken Step 3. Compensate (mitigate)- the appropriate mitigation is required for the impacts that cannot be avoided. The amount and quantity of mitigation may not substitute for avoiding and minimizing impacts. aka step 1 and 2 cannot be substituted.

How did the restoration of San Fran Bay come about?

Citizens groups started restoration. Goal was to restore 100,000 acres. Governmental entities and non governmental organizations also got involved.

What is the most common restoration?

Coastal wetland restoration. Because they provide flood control and mitigation.

What type of hydrophyte is used in salt marsh wetland restoration the most and why?

Cord grass, Spartina spp. because rapid seed dispersal causes quick revegetation in intertidal areas.

What does restoration of mangroves depend on?

Depends on restoring intertidal conditions -salt marsh. it requires physical planting of small tress or seed. Restoration is attempted in many parts of the world

What is the "No net loss guidance"

Ensure protection of regulated wetlands OR allow for creation of new wetland or restorations of existing, degraded wetland as compensation for filling wetlands.

What is the San Fran Bay Restoration Authority?

Established in 2008, funded by taxpayers (10-20$ per person per year). It is a regional government agency tasked with generating and allocating resources for, restoration, enhancement, protection and enjoyment of SF bay wetlands and wildlife habitat. Acts as command central for restoration efforts.

Why is restoring tidal condition so important in restoring salt marshes?

Excessive freshwater inputs limit salt marsh plants and encourages growth of non-natives. Tidal conditions eliminate human created barriers like dunes and roads. To restore, install tide gates or enact periodic breaches.

Describe the USDA Wetland Reserve program's Mississippi River Valley Project

Forested wetland restoration. 78,000 ha reforested 14,000 in application . Have subsides for restoration and 430 conservation easements (others are 30-year easements) 10-year restorations cost-share.

In terms of considering hydrology for wetland placement, what is the best inflow source? Why? What is a challenge of it?

Groundwater. Because it is more predictable and less seasonal. It is easier to construct and potentially has no future maintenance. However, setting desired hydroperiod is hard.

In terms of creating or restoring wetlands, what are factors that need to be remembered when dealign with hydrology?

If water table is low, construct wetland near streams so they can be used as a source. Control structures can supply and regulate inflow of these sources. Embankments are often needed because of mammal issues. These things increase cost however, and require long-term maintenance.

Describe the Snohomish County Airport, WA.

In the late 1990s the airport's runway safety projects posed threats to several small wetland. To offset effects, the established new wetlands in advance of degradation to existing wetlands. They created 50 acre and 13 acre wetland sites near airport. They developed boardwalks and environmental displays.

Why is is important to place a wetland on already occurring hydric soils?

It speeds up succession since it takes 2-100 years for hydric soils to develop and organic content in soils increase 1% every 3 years. Hydric soils often have seed banks and the proper soil chemistry needed for wetland processes.

Why would wetlands be created?

Make up for past losses. Ex. Upper Susquehanna Coalition NY and PA constructed over 400 vernal pools for amphibians and aquatic invertebrates OR Mitigate approved losses- this is regulates and usually involved engineering and environmental consulting firms.

Describe both the South Bay Restoration and the Napa-Sonoma Marsh restoration

Napa-Sonoma- 20 year project that restored 12,000 acres. It was formerly a industrial salt pond, that created the diluter by-product "bittern". Pipeline to supply recycled water and reduce salinity was incorporated into goals. Project almost completed. South Bay- Industrial salt pond bought from Cargill Inc. in 2003. Restoration of 15,000 acres. $100 million provided by federal governments, HP and Moore foundations

What happens when peatlands are drained?

Natural succession rarely restores peatlands. This is the most difficult type of restoration because hydrology must be restored and restoration would have to occur over decades.

What plants should we watch for in the first few years of wetland restoration/mitigation and why?

Plants that "choke" wetland (i.e. change hydrology, create sediment, fill in wetland) Native: Typha, Ceratophyllum and Myriophyllum. Invasive: Phragmites, Lythrum salicaria

What are some of the reasons that wetland creation doesn't work?

Poor placement: Land availability, hydrology, and soils not creating equivalent wetland (mitigation) long term maintenance

Under compensatory mitigation the prescription varies and ranges how?

Prescription varies by state and particular situation. Replacement can range from 1:1 to 30:1.

Describe the Cockroach Bay Restoration

Restoration of 500 acres of former farmland and shell mining pits near Tampa Bay, FL. The land was purchased by the state in 1991 and the project took 21 years with 2,500 volunteers, environmental groups, and government agencies. Restored: 280 acres: freshwater wetlands estuaries and 220 acres coastal upland. Buffered by 150 acres of coastal uplands. Connected with 8.000 acres of parks and reserves During the process 175 tons of garbage hauled away, 500,000 cu tons of recycled dredge material used in mining pits. Thousands of upland and wetland plants established. Now open to recreation 300 species of birds observed.

Under compensatory mitigation, is impacts cannot be avoided or minimized....

Restoration of degraded wetlands Establishment of new wetland Enhancement to increase functions in existing wetlands Preservation- permanent protection of existing wetlands

Why did the SF Bay become so degraded?

Since 1849 gold rush CA has become extremely populated. Bay is a 40 million acre watershed (40% of state drains to bay). Since population, 90% of wetlands have been destroyed for agriculture and development.

What are some challenges of the San Fransisco Bay restoration?

The size of the ares (three cities San Fran , Oakland, San Jose) covered 9 counties, hundreds of municipalities, ~1600 square miles and 7.5 million people. Land that needed to be restored was valuable (housing, commerce, agriculture).

Describe the work in Quebec to restore peatlands

They are restoring hydrology and are blocking bog drains to reduce oxidation of o-matter. Establish sphagnum and other bog vegetation.

Why is is harder to restore forested Wetland?

We have less experience because it is more difficult. Forest regeneration takes decades and the compete with emergent plants and shrubs so it might not work

Why is placement essential when restoring wetlands

Wetlands need to be created with placement in mind because of the effects topography, soils, hydrology and human impacts can have on a wetland.

Where is restoration more successful?

Where natural examples exist (i.e. "reference wetlands". You can assess succession, biodiversity and ecological functional and how to control invasive plants.

What is wetland mitigation?

creating new wetlands to make up for wetland losses associated with development or other land use changes

Mitigation banking

developers pay into mitigation banks that work toward creation or restoration of larger areas; credits are sold to developers

What is causing the degradation on mangrove wetlands?

mangrove cleared for aquaculture (shrimp and fish) . These artificially ponds are useful for 5-6 years and then the sulfur levels become toxic. So 100,000 ha of ponds have been created by destroying mangroves, and then are abandoned. 3,000 ha of mangrove are cleared in Philippines per year.

What is Wetland Restoration

returning degraded natural wetland to their natural, pre-disturbance state; corrects damage to hydrology, plant community, soils, and topography; can be a part of mitigation