Carmel River Floodplain Restoration and Environmental Enhancement (Carmel River FREE) Project

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An environmental topic examined by the ENVS 560/L Watershed Systems class at CSUMB.

Carmel River Floodplain Restoration and Environmental Enhancement Project long term restoration plans. Image sourced from the Big Sur Land Trust blog

Summary

The Carmel River Floodplain Restoration and Environmental Enhancement Project (Carmel River FREE) is a collaboration between the Big Sur Land Trust (BSLT) and the County of Monterey Resource Management Agency to reduce the flood risk for businesses and residences in the Lower Carmel Valley and restore the active floodplain. The project encompasses the following components: [1] [2] [3]
Location of the Carmel River FREE project. Image sourced from the Big Sur Land Trust.
  • Removal of 1,470 ft of levee on the south side of the Carmel River to allow river access to the Odello East floodplain,
  • Replace 360 ft of the Highway 1 roadway with an elevated causeway to allow floodwater movement under the highway and connect the floodplain to the Carmel River Lagoon,
  • 100 acres of agricultural land graded to mimic the historic floodplain including braided off-stream channels and depressions for sediment settlement,
  • 90 acres of riparian and grassland habitat restoration and monitoring,
  • 23 acres reserved for organic agriculture, elevated above the 100-year floodplain.

Construction is projected to begin in early 2018 and be completed within a year. [4]

Location

Carmel River FREE will restore floodplain in the Lower Carmel Watershed in Carmel Valley, Monterey County, California. The project site is east of the Highway 1 bridge over the Carmel River.

Background

In 2010 BSLT proposed alleviating the risk of flooding in the Lower Carmel Valley by restoring the floodplain instead of expensive levee reinforcements. [5]

Part of the Carmel River State Beach and Palo Corono Regional Park were contributed by California State Parks and the Monterey Peninsula Regional Park District to Carmel River FREE. Clinton and Margaret Eastwood are donating 82 acres (the Odello East parcel) to add to 49 acres already owned by the Big Sur Land Trust. [2] Water rights for the Odello East property will be re-allocated from crop irrigation to river and lagoon enhancement (46.2 acre-feet per year (afy)) and municipal use (85.6 afy). [6] [7]

Objectives

Floodplain and habitat restoration

In addition to restoring 100 acres of floodplain, riparian, and grassland habitat, Carmel River FREE will connect a 1997 Caltrans restoration site to the west of Highway 1 with the Carmel River Lagoon Enhancement Project (completed in 2004 by California State Parks). Together, these projects create a wildlife corridor along the Carmel River and maintain important habitat for migratory birds, protected CA red-legged frogs and Steelhead, and state-listed Western pond turtles. [3]

Reduced Groundwater Pumping

As a result of transferring water rights from crop irrigation to river and municipal use, groundwater pumping will be reduced by 46.2 afy. [6] Hopefully this will improve base flows in the Carmel River and lagoon. [2]

Improved water quality

A sediment sequestration depression will reduce the amount of nutrients and sediment that flow into the lagoon and the Carmel Bay. [2]

Reduced flood risk

Monterey County Service Area 50 (CSA-50) includes the Crossroads shopping center and private residences in the Riverwood, Arroyo Carmel, and Mission Fields communities. Property owners in CSA-50 have voluntarily elected to pay additional taxes and fees in exchange for extra services and improvements not included in basic services provided by the county.[8] Properties located in CSA-50 are within the 100-year floodplain limits of the Carmel River North Overbank; CSA-50 has 69 Repetitive Loss Properties, 63% of such properties in Monterey County. [9] Flooding in 1995 damaged 220 residences in CSA-50 and destroyed the Highway 1 bridge. [10] Floodplain restoration will give water in the Carmel River an appropriate place to spill over in high flow events so that businesses and residences are protected. Without Carmel River FREE, the County of Monterey would have to reconstruct existing levees to meet Federal Emergency Management Agency (FEMA) standards, costing an additional $14 million. [2]

Public access

Carmel River FREE includes plans for recreational trails that will connect Carmel River State Beach with Palo Corona Regional Park.

Funding

The total estimated cost of Carmel River FREE is $24 million. [2]

The Big Sur Land Trust secured $14 million from the California Water Resources Agency, US Environmental Protection Agency, US Fish and Wildlife Service, California Coastal Conservancy, California Department of Transportation, and California Wildlife Conservation Board. [4]

The 2014 Monterey County Service Area 50 Flood Control Report [9] estimated that the Carmel River FREE project would reduce the cost of flood control improvements from $25,771,000 to $11,322,000, saving the County over $14 million.

Previous Studies

CEQA/NEPA

The US Fish and Wildlife Service and Monterey County are the lead agencies for NEPA and CEQA documents, respectively. A combined CEQA/NEPA draft is under review and will be available to the public in the summer 2016. [2]

Methods and Tools

Hyrdologic: Balance Hydrologics used HEC-RAS modeling software to simulate flooding along the Carmel River and determine the 100-year floodplain for the Lower Carmel Valley. [9]

Biological: H.T. Harvey & Associates completed an environmental assessment focusing on biological evaluations and permitting issues for the Carmel Lagoon. The report documented habitat types, special status species, and special status habitats found within the lagoon and surrounding area. [11] This document was part of the 2013 Ecosystem Protection Barrier and Scenic Road Protection Feasibility Report. The most recent biological assessment for the Carmel River FREE project had not been released as of April 2016.

Biological assessments and hydrologic reports for the Lower Carmel River:

2009 Riparian Corridor Monitoring Report, MPWMD

MPWMD 2013-2014 Mitigation Program Report

Environmental and Biological Assessment of Portions of the Carmel River Watershed

CSA-50 Final Lower Carmel River Stormwater Management and Flood Control Report

Parties Involved

Organizations

Agencies

Consultants

More information on other work by these firms can be found on the List of Environmental Consultants working in the California Central Coast Region.

Community Members

  • Clinton and Margaret Eastwood

Links

References

  1. Carmel River FREE, BLST blog
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Carmel River FREE handout, BSLT
  3. 3.0 3.1 Lower Carmel River and Lagoon Floodplain Restoration and Environmental Enhancement Project, BSLT
  4. 4.0 4.1 Freeing the river to use its floodplain, BSLT newsletter
  5. Carmel River FREE Project hopes to relegate flooding to history, Monterey County NOW
  6. 6.0 6.1 Water Right Change Petition Draft Environmental Impact Report
  7. Eastwood-Odello Water Right Change Petition Final Environmental Impact Report
  8. CA Property Tax Information
  9. 9.0 9.1 9.2 CSA-50 Final Lower Carmel River Stormwater Management and Flood Control Report
  10. Historical flooding in Monterey County
  11. EPB and Scenic Road Protection Feasibility Report.

Disclaimer

This page may contain student work completed as part of assigned coursework. It may not be accurate. It does not necessarily reflect the opinion or policy of CSUMB, its staff, or students.