Matagorda Island Marsh Restoration An Adaptive Management Approach by Coastal Bend Bays & Estuaries Program

Transcription

1 Matagorda Island Marsh Restoration An Adaptive Management Approach by Coastal Bend Bays & Estuaries Program 1957: After Levees 1930: Before Levees

2 Matagorda Island: Site Location Texas Coastal Bend Calhoun County Aransas National Wildlife Refuge Matagorda Island Unit 15,000 acre Western Marsh

3 Matagorda Island: Site History 1930s little evidence of human impact 1940s 1960s taken over by the Air Force, no public access was allowed Matagorda Island Bombing and Gunnery Range system of levees and ditches partitioned the site by mid 1950s active dewatering was initiated 1970s 1990s ownership transferred to U.S. FWS and TPWD U.S. FWS: habitat and wildlife management (migratory birds, Whooping Cranes) TPWD: public use management 2000s today U.S. FWS: on-going effort to restore hydrology to 1930s conditions

4 1930: No Levees More Open Water

5 1957: Levees More Sand and Mudflats

6 2007: Significant Non-Native Vegetation

7 Project Goal Maximize productivity within 15,000 acres on Matagorda Island by enhancing tidal circulation and water exchange. USFWS State and Federally Listed Species of Concern Found on Matagorda Island American Alligator, Aplomado Falcon, Arctic Peregrine Falcon, Bald Eagle, Botteri s Sparrow*, Brown Pelican, Green Sea Turtle, Hawksbill Sea Turtle, Kemp s Ridley Sea Turtle, Least Tern, Leatherback Sea Turtle, Loggerhead Sea Turtle, Mountain Plover, Peregrine Falcon, Piping Plover, Reddish Egret, Roseate Tern*, Sooty Tern*, Southern Yellow Bat, Swallow-tailed Kite, Texas Diamondback Terrapin, Texas Horned Lizard, West Indian Manatee*, White-faced Ibis, White-tailed Hawk, Whooping Crane, Wood Stork, Zone-tailed Hawk (* = Species outside of its normal range)

8 Management Plan: Objectives In 2006, the Refuge approached CBBEP to seek funding assistance for the development of a comprehensive management plan that would: 1. Increase tidal exchange between the bay and marsh system. 2. Promote circulation and exchange between interior cells. 3. Reduce maintenance costs for existing system of control structures. 4. Maintain access via critical levee roads for monitoring and law enforcement.

9 Management Plan: Considerations Difficulty of data collection and site characterization very little or no existing tide, current, or water quality data very large, complex site (15,000 acre marsh complex) remote location (boat/barge access only) Maintain interior levee system for transportation and maintenance Other levees: Removal preferred, but some locations must be intact to allow access to other locations may necessitate delaying restoration at higher priority locations Ability to complete restoration actions in phases allow for varying amounts of available funding no work during Whooping Crane wintering season (October 15 April 15) majority of construction window coincides with hurricane season

10 Adaptive Management Plan (AMP) Matagorda Island s 15,000-acre Western Marsh is a large and complex system. Any attempt at a comprehensive characterization would be difficult and expensive. An adaptive management approach was utilized to minimize initial planning and development costs. figure out what you want, figure out how it works, make a change, figure out what happened, and do it better the next time. - Joe Billy Bob (HDR)

11 AMP: Goals and Targets

12 AMP: Conceptualization of System

13 AMP: Conceptualization of System

14 AMP: Learning (Monitoring)

15 AMP: Process for Improving Future Management Decisions

16 AMP: Phase 1 Prioritized Restoration Action Locations

17 Restoration Actions: Construction Considerations Minimize Design Costs Standardized Set of 3 Culverts Initial restoration actions consisted mostly of culvert installation/replacement Focus is gradually shifting towards levee removal Future: additional earthwork (new channels) to enhance flow??

18 Restoration Actions: Outer Rim Culvert Replacement Before After

19 Restoration Actions: Redfish Landing Culvert Replacement Before After

20 Restoration Actions: Darkwater Levee Removal Before

21 Restoration Actions: Darkwater Levee Removal After

22 Restoration Actions: Benefit Map

23 Summary of Project Accomplishments Development of Matagorda Island Adaptive Management Plan (Phase 1 and Phase 2) Restoration actions completed at 11 locations Enhanced circulation throughout approximately 3,100 acres of wetlands Treated approximately 400 acres of uplands for non-native vegetation Finishing second round of the adaptive management cycle Starting third round of prioritizing action items

24 Funding and Project Partners Total Project Funding Through CBBEP: $630,000 $410,000 TCEQ/EPA; $220,000 USFWS-Coastal Program $70,000 AMP Development and Updates; $560,000 Restoration Actions Key Funding Partners U.S. Fish & Wildlife Service-Aransas National Wildlife Refuge U.S. Fish & Wildlife Service-Coastal Program Texas Commission on Environmental Quality U.S. Environmental Protection Agency Gulf of Mexico Program Friends of Aransas and Matagorda Island Tivoli Independent School District Texas General Land Office-Coastal Impact Assistance Program (future funding partner) HDR Engineering, Inc

25 References and Contact Information CBBEP (follow link to Featured Projects ) U.S. FWS Aransas National Wildlife Refuge Dustin Cravey Project Manager Coastal Bend Bays & Estuaries Program dcravey@cbbep.org

26 Discussion / Questions