Yamilett Carrillo-Guerrero

University of Arizona, School of Renewable Natural Resources

Restoring Colorado River Delta Wetlands

Colorado River Delta, Mexico

SonoraBajaCalifornia

ArizonaCalifornia

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Year

Mm

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Flows to the Colorado River Delta 1950-2000

CA

Mexicali

San Luis R.C.

BAJA CALIFORNIA

SONORA

AZ

Colorado River Riparian CorridorRio Hardy

Cienega de Santa Clara

El Doctor

Intertidal mudflats

Morelos DamNIB

SIB

Limitrophe ZoneÊÚÊÚ

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EW

S

10 0 10 20 30 40 50 Kilometers

Detections / detecciones

Riparian vegetation / vegetacion riparia

Saltcedar / pino salado

Emergent vegetation / vegetacion emergente

Mudflats / planicies lodozas

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Ecozones in the Colorado River Delta

• Critical migratory site and breeding area for sensitive species

• Recognition: Biosphere Reserve, Ramsar Convention, WHSRN, and NAWCA

The Colorado River Delta, Mexico

The Need for Restoration in the Colorado River Delta

* Major causes for wetland loss in the delta:

2. Agricultural expansion

1. Lack of instream flows

The Need for Restoration in the Colorado River Delta

* 76 % of delta wetlands were lost in last 100 years.

* Invasion of non-native species (Tamarisk spp.)

Protected Species in Mexico and US that occur the Colorado River Delta

• Yuma Clapper Rail• California Black Rail • Least Bittern• Least Tern• Bald Eagle• Peregrine Falcon• Prairie Falcon• Brown Pelican• Wood Stork • Savannah Sparrow• Willow Flycatcher

Natural Restoration of Riparian Areas

Water Management Policies and Regulations

Restoring the Colorado River Delta: A Binational Effort

Water Management

1) Estimates of 0.5% of annualized mean flow for Riparian Corridor.

• Three-month spring flow of 3 x 108 m3 every 4 years , and

• Perennial flow of 4 x 107 m3

Restoring the Colorado River Delta: A Binational Effort

2) Timing and consistency of excess flows.

3) Management Plan for Colorado River delta floodplain

2) Environmental quota.

Policies and Regulations

Restoring the Colorado River Delta: A Binational Effort

1) Recognition of ecosystem as user entitled to Colorado River water.

3) Commitment to secure instream flows in the delta.

4) Involvement of local communities in the restoration process.

Policies and Regulations

Restoring the Colorado River Delta: A Binational Effort

Restoration Initiatives from Local Communities

Proposals from Delta Communities

* Formal commitment of farmers not to take water out of river if an environmental quota was to be established by US and Mexico.

* The river and its banks should be declared a protected natural area.

* Restore riparian forests along the River.

* Each user should contribute to instream flow needs, proportionally to its use of water.

* Conservation easements

Proposals from Delta Communities

Pilot Projects of Restoration in the Delta

1. Environmental use of agricultural drainage water

2. Community wetland management and restoration

3. Farmland retirement for wetland restoration

GENERAL PURPOSE

To determine if a program to change land uses of

farmland could be established in the Colorado River

delta, Mexico, with the purpose of restoring wetland

areas.

OBJECTIVES

a) Assess landowners disposition to change land use from agriculture to wetland restoration projects

b) Determine landowners’ disposition to lease their water rights for wetland conservation

c) Estimate the costs of a program of retiring the agricultural land.

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Riparian Potential

Marshland Potential

USA

MEXICO

MEXICO

2. SURVEY

* Personal interviews

* 32 Farmers contacted in Region 1 (38% area of study)

* 16 Farmers contacted in Region 2 (30% area of study)

* Duration: 15 min. questionnaire, 1 hour interviews

* Pre-tested with farmers outside study area

QUESTIONNAIRE

* Topics:

a. Farmers’ perception regarding the Colorado River

b. Farmland characteristics

c. Farmland retirement program

d. Rent of water-rights

Land and Water Availability and Costs

Region Land

(Ha)

$ Land

($US/yr)

Water

(Ha)

$ Water

($US/yr)

1- Riparian

229(566 acres)

$298,616 136.5(1,106 af)

$36,991.5

2- Marsh

115(284 acres)

$74,980 77(624 af)

$20,867

Total

344 Ha

850 acres $373,596

213.5 Ha

(1,730 af) $57,858.5

International Wildlife Refuge in the Limitrophe Area

•Proposed by Cocopah Indian Tribal Council

•Encompass Limitrophe Area-International Boundary(Arizona-Baja California)

•Purpose: Preserve the Riparian Corridor in the InternationalBoundary

•US Agencies supporting: USFWS, US Border Patrol•US Agencies against: IBWC, BOR?

•Mexico’s position: Federal Government do not know, Landowner’s in the area want the riparian corridor a protected natural area

Why an InternationalWildlife Refuge?

CONCLUSIONS

1. Ecosystem restoration is feasible in the Colorado River delta.

2. Restoration process could be embraced and maintained by local communities.

3. Farmers’ participation could yield more hectares restored than land purchases.

4. Rent of Water Rights in Mexico would not be enough to restore the delta.

As functions and values of wetlands in the Colorado

River Delta provide benefits that do not consider

political boundaries, management and restoration

of the delta ecosystem

should be worked out as

a bi-nationally shared

responsibility.

Sonoran Institute Pronatura Sonora

Wallace Foundation

This research was financed with grants from:

Environmental Defense