Restoring natural habitats to their original landscape supports species. In 2016, habitat covered ~70,000 acres of the Delta. By 2022, another 8,500 acres were restored.

The Measure

Restore large areas of natural communities for habitat connectivity and crucial ecological processes, along with supporting viable populations of native species.

  • Expectations

    • Increase acres of natural communities to contribute to suitable habitats for fish and other wildlife, restored habitat connectivity, and viable populations of native species
  • Performance Metrics

    •    Acres of natural communities restored
    •    This metric will be updated and evaluated every five years

Acres of Natural Communities Restored by Ecosystem Types

The bar graph displays habitat baseline data from the 2007 Vegetation Classification and Mapping Program dataset by ecosystem type in the Sacramento-San Joaquin Delta. The ecosystem types shown were condensed and categorized for visualization purposes. For a full description of the ecosystem types, please refer to the table under the Metric, Baseline, and Target section. The blue bars represent the baseline acreages, and the green bars represent the target acres needed by 2050 to improve ecosystem health. The peach bars represent the 2016 total acreages per habitat type. These conditions are based on the 2016 Vegetation Classification and Mapping Program dataset.

Acres of Natural Communities Restored by Ecosystem Types Bar Graph

The bar graph shows varied results in ecosystem types from 2016. Grassland areas, for example, were categorized as agricultural and urban areas. This is partly due to the timing of vegetation flyovers, which influenced how habitat was categorized. Some areas were used as grassland in the winter and as agricultural fields during the summer and fall. Differently, tidal wetlands and vernal pool complexes were overestimated due to error in GIS processing of up to 25%, exaggerating the baseline.

Restoration Project Numbers

Since 2016, many ecosystem restoration projects have been completed, restoring about 8,480 acres of additional habitat. The table below summarizes major habitat types in restoration projects between 2016-2022. During this timeframe, another 5,000 acres were in progress and 6,000 acres were being planned. 

Next data update: Acres of natural communities will be calculated and evaluated from Delta and Suisun Marsh Vegetation Classification and Mapping updates. The next update for this visualization will be in 2024.

Historically, the Delta and Suisun Marsh supported more than 650,000 acres of natural communities including riparian, wetland, and oak savanna. However, more than 90 percent of those ecosystems have been lost through land conversion to agriculture and urban land uses. Reestablishment of some of these natural communities on the landscape will provide critical ecological functions such as aquatic primary production and vegetation community succession, as well as physical space, connectivity, and habitat structure that is important for native species recovery.

Planning and management efforts, such as recovery plans, species-specific resiliency strategies, and conservation strategies, identify specific actions for ecosystem preservation and restoration to meet species’ needs. At least 11 recovery and conservation plans exist that have geographic coverage in the Delta and Suisun Marsh. These plans identify restoration and management actions needed to achieve the recovery of 35 species of special-status plants and 86 fish and wildlife species of conservation concern (Appendix Q4, Delta Plan, 2022). Nearly half of these species of conservation concern are endemic to California.

Delta restoration targets are based on recovery and conservation plans and are organized by historical natural community types. Natural community types are classified by plant community structure and physical characteristics such as hydrology and landscape position. Restoration of complex ecosystems will require the reestablishment of native vegetation communities. Restoring a variety of native vegetation cover types will promote ecological resilience and native biodiversity. Large areas of natural communities will provide functional, diverse, and interconnected habitats suitable for fish and other wildlife and support the recovery of native species.

This performance measure tracks the acres of natural communities by ecosystem type restored in the Delta and Suisun Marsh.

Map Visualization of Baseline Ecosystem Habitat Types in the Delta.

Map Visualization of Baseline Ecosystem Habitat Types in the Delta

Modern habitat community types in the Delta and Suisun Marsh are used for setting baselines for habitat acreages. Other habitat types such as managed wetlands and agricultural habitats are not being tracked for this performance measure.

Targets for each natural community (ecosystem) type were derived from conservation and restoration targets identified in conservation and recovery plans within the Delta and Suisun Marsh (Delta Plan, Appendix Q4). Where conservation and recovery plans overlap, habitat acreages were combined into a single target.

Restoration targets from plans with geographically larger footprints are proportionally scaled for the Delta and Suisun Marsh regions. The table below lists the net increase of target acres by ecosystem type and associated the recovery and conservation plans within the Delta and Suisun Marsh used for setting the target acres of net increase by ecosystem type.

Ecosystem Type

Target Acres Net Increase

Source Reference (Recovery and Conservation Plans

Seasonal Wetland

Wet Meadow

Nontidal Wetland

19,000 acres

 

Central Valley Flood Protection Plan (DWR 2016b)

Willow Riparian Scrub/Shrub

Valley Foothill Riparian

Willow Thicket

16,300 acres

Central Valley Joint Venture Implementation Plan (Dybala et al. 2017b)

Tidal Wetland

32,500

Central Valley Flood Protection Plan (DWR 2016a, 2016b); Central Valley Flood Protection Plan (CVFPP 2017b); Giant Garter Snake Recovery Plan (USFWS 2017); Tidal Marsh Recovery Plan (USFWS 2013); Suisun Marsh Habitat Management Plan (USBR, USFWS, CDFW 2013)

Stabilized Interior Dune Vegetation

640 acres

A Delta Transformed (SFEI-ASC 2014)

Oak Woodland

13,000 acres

Central Valley Joint Venture Implementation Plan (DiGaudio et al. 2017b)

Grassland

No net loss

A Delta Transformed (SFEI-ASC 2014)

Vern Pool Complex

670 acres

Conservation Measure 9, Bay Delta Conservation Plan (DWR 2013)

Alkali Seasonal Wetland Complex

230 acres

Conservation Measure 9, Bay Delta Conservation Plan (DWR 2013)

Each chapter of the Delta plan includes strategies to achieve the goals of the plan. These strategies are general guidance on achieving the objective laid out in the plan and in the Delta Reform Act of 2009. Associated with these strategies are recommendations. The recommendations describe more specific and implementable actions to support the achievement of Delta Plan strategies. Strategies and recommendations may also have associated performance measures. Delta Plan performance measures track progress in achieving desired outcomes for the Delta Plan. Below are the strategies and recommendations associated with this performance measure. 

Strategy
  • Restore Ecosystem Function
Recommendations

ER RF. Delta Plan Interagency Implementation Committee Restoration Forum

Metric

Acres of natural communities restored. This metric will be updated and evaluated every five years.

Baseline

Acres of natural communities from the 2007 Vegetation Classification and Mapping Program (VegCAMP) dataset by the California Department of Fish and Wildlife (CDFW), as designated below.

Ecosystem Type

Baseline Acres (2007 VegCAMP)

Seasonal Wetland

Wet Meadow

Nontidal Wetland

5,100

Willow Riparian Scrub/Shrub

Valley Foothill Riparian

Willow Thicket

14,200

Tidal Wetland

19,900

Stabilized Interior Dune Vegetation

20

Oak Woodland

0

Grassland

33,000

Vernal Pool Complex

5,100

Alkali Seasonal Wetland Complex

700

Target

Net increase of target acres of natural communities by 2050 are listed below.

Ecosystem Type

Target Acres Net Increase (From Baseline Acres)

Total Area (Baseline Acres Plus Net Increase)

Seasonal Wetland

Wet Meadow

Nontidal Wetland

19,000

24,100

Willow Riparian Scrub/Shrub

Valley Foothill Riparian

Willow Thicket

16,300

30,500

Tidal Wetland

32,500

52,400

Stabilized Interior Dune Vegetation

640

660

Oak Woodland

13,000

13,000

Grassland

No net loss

33,000

Vernal Pool Complex

670

5,770

Alkali Seasonal Wetland Complex

230

930

To provide a short-term assessment of progress toward the restoration targets, intermediate milestones are evaluated every decade toward the 2050 target date. Assessments of the performance measure will consider the existing state of restoration in the Delta and disclose conditions impacting the rate of restoration interim progress.

 

Ecosystem Type Baseline Target Area (Baseline Acres Plus Net Increase)
2030 2040 2050

Seasonal Wetland

Wet Meadow 

Nontidal Wetland 

5,100 11,400 17,700 24,100

Willow Riparian Scrub/Shrub 

Valley Foothill Riparian

Willow Thicket 

14,200 19,600 25,100 30,500
Tidal Wetland 19,900 30,800 41,600 52,400
Stabilized Interior Dune Vegetation 20 240 450 660
Oak Woodland 0 4,400 8,700 13,000
Grassland 33,000 33,000 33,000 33,000
Vernal Pool Complex 5,100 5,300 5,500 5,700
Alkali Seasonal Wetland Complex 700 780 860 930

Tools evaluating restoration effectiveness and natural community conditions will be considered in interpreting this performance measure. These may include Wetland Regional Monitoring Program (WRMP) and Habitat Development Curves for wetland and aquatic resources, Tidal Wetland Monitoring Framework for the Upper San Francisco Estuary for fisheries benefits, and project-specific long-term monitoring and operations plans. 

Methods
  1. Use the updated VegCAMP datasets (Delta Vegetation and Land Use, Vegetation – Suisun Marsh). 
  1. Categorize VegCAMP Associated Native Vegetation Community type (VegCAMP CaCode) into associated natural communities (ecosystem types). 
  1. Calculate total acres by each of the natural communities and calculate the net increase over the five-year period and against the baseline. 
Data Sources

VegCAMP: Delta Vegetation and Land Use - 2011 [ds292]

VegCAMP: Vegetation - Delta Vegetation and Land Use Update - 2016 [ds2855]

VegCAMP: Vegetation – Suisun Marsh [ds2676]

SFEI: Landscape Scenario Planning Tool

Dylan Chapple: The Future of Restoration in the Delta Numbers - DPIIC Presentation

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