Dredging for diplomacy
1 / 28

DREDGING FOR DIPLOMACY? - PowerPoint PPT Presentation

  • Uploaded on

DREDGING FOR DIPLOMACY?. THE BORDER ENVIRONMENT AT RISK McGeorge Law School February 19, 2005. presentation overview. the Colorado River limitrophe the dredging project environmental alternative. Less than 1% of the Colorado’s water reaches its delta.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'DREDGING FOR DIPLOMACY?' - richard_edik

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Dredging for diplomacy l.jpg



McGeorge Law School

February 19, 2005

Presentation overview l.jpg
presentation overview

  • the Colorado River limitrophe

  • the dredging project

  • environmental alternative

Slide7 l.jpg

  • Morelos Dam

    • final point of diversion

    • downstream flows erratic

    • siltation

    • overbank flooding

Slide9 l.jpg

flooding in limitrophe…

native habitat created

Limitrophe amphibians and mammals 2003 l.jpg

Soft-shelled turtle

Side-blotched lizard

Tree lizard

Desert spiny lizard




Pygmy pocket gopher

Desert pocket mouse

Merriam’s kangaroo rat

Deer mouse



Domestic dog


limitrophe amphibians and mammals, 2003

Limitrophe birds 2003 high regional importance l.jpg

Abert’s towhee


Ladder-backed woodpecker

Cliff swallow

Song sparrow

Common yellowthroat

Blue grosbeak

Lesser goldfinch

Hooded oriole

Bullock’s oriole

Ash-throated flycatcher

Crissal thrasher

Yellow-breasted chat


Black chinned hummingbird

Inca dove

Bronzed cowbird

Yellow-billed cuckoos

Cinnamon teal

Common moorhen

Pied-billed grebe

Green heron

Yuma clapper rail

Southwest willow flycatcher

limitrophe birds, 2003high regional importance

Slide12 l.jpg

Southwest willow flycatcher

  • neotropical migrant

  • riparian obligate

  • prefers backwaters

  • endangered in US (300-500 breeding pairs)

Slide13 l.jpg

Yuma Clapper Rail

  • lives in marshes, wet riparian margins and backwaters

  • endangered in US (1500 individuals)

Public interest in limitrophe environment l.jpg
public interest in limitrophe environment

  • Cocopah Tribe proposal in 2002 to create international protected area in limitrophe

  • Surveys in US and Mexico support protection of limitrophe ecosystem

  • Yuma birding festival

  • US-Mexico Minute 306 recognizes importance of limitrophe

  • BLM considering Area of Critical Environmental Concern status

Management for ecosystem l.jpg
management for ecosystem

  • perennial flow

  • occasional overbank flooding

  • natural river meanders

  • conservation and restoration of cottonwood-willow forests

  • protection and creation of backwaters

International boundary and water commission l.jpg
International Boundary and Water Commission

  • Relevant mandates include:

    • Minute 217 (1964)

      Relies on a 1940’s flow study

      Requires flood capacity of 140,000 cfs today considered the 10,000-year flood

      - Boundary Treaty (1970)

      Boundary determined by river channel

Ibwc project l.jpg

  • Maintain flood capacity

  • Rectify US-Mexico boundary

  • Demarcate US-Mexico Boundary

  • Levee-to-levee capacity of 140,000 cfs

  • Pilot channel of 15,000 cfs

Ibwc project19 l.jpg

  • dredge channel to establish and maintain bare-sand corridor, 300-750 feet wide

  • Severely degrade existing native habitat

    Environmental Defense response:

    • is project necessary?

    • can design avoid habitat destruction?

Is the project necessary l.jpg
Is the project necessary?

  • flood capacity of 140,000 cfs was established in 1940’s

  • Projects constructed since then include Flaming Gorge, Glen Canyon Dam, CAP, Morelos Dam and more

  • Phoenix, Las Vegas, San Diego have boomed

  • Today 140,000 cfs is the 10,000-year flood

Can design avoid habitat destruction l.jpg
Can design avoid habitat destruction?

  • IBWC is planning 15,000 cfs pilot channel to increase levee-to-levee capacity AND to demarcate boundary

  • Existing levees deficient only in northern 4 miles of limitrophe

Integrated goals l.jpg
integrated goals

  • protect life and property to level determined by cost-benefit analysis

  • address territorial concerns

  • enhance ecosystem values

  • contribute to local economy by increasing tourism value

Preliminary design recommendations l.jpg
Preliminary Design Recommendations

  • Maximize use of levees to minimize need to destroy native habitat

  • Revisit need for 15,000 cfs pilot channel. Consult with fluvial geomorphologists to develop levee protection that eliminates or minimizes need for pilot channel.

Slide26 l.jpg

Slide27 l.jpg

  • Do not strand existing native riparian forest by diverting elsewhere the existing channel and the flows it conveys.

  • Incorporate restoration of cottonwood-willow trees, oxbows and backwaters, and other important riparian habitats into final alternative.

Slide28 l.jpg

Where things stand… diverting elsewhere the existing channel and the flows it conveys.

  • IBWC withdrew contract in summer 2004

  • IBWC and CILA meeting to reassess flood control needs

  • Environmental Defense working on a design alternative to address “reasonable” flood control, boundary rectification, and habitat augmentation