Muddy Waters: Silt and the Slow Demise of Glen Canyon Dam

  • The ever-migrating waterfall on the Lower San Juan River.

    Craig Childs
  • The silt-laden Colorado River was revealed above Hite Marina during the drought year of 2003, with the lake level down 100 feet.

  • The San Juan drops 15 feet into a violent churn at the waterfall in its new channel.

    Craig Childs
  • Debris floats on the upper reaches of Lake Powell, no longer carried by the current of the San Juan.

    Craig Childs
  • The river disappears into Lake Powell, where the bathtub ring shows the lake level during highwater years.

    Craig Childs
  • Craig Childs

 

Page 4

It isn't just psychological, though. The river corridor is different. Birdlife flourishes. Troops of Canada geese hold the ground at every bend. I catch up with a coyote swimming across the river, and she climbs to shore 10 feet away, bony with dripping fur. With a quick shake, the animal fluffs herself and trots downstream. I keep pace, paddling just off her shoulder. She squats to put a scent on the ground, with a candidness I am unaccustomed to among coyotes. I try not to stare, impolite at such close range. We continue together until she finds herself cut off by a small backwater bay. She stops and finally looks at me with dark, inquisitive eyes. Then she trots the other way, and the current carries me downstream.

That bay is the first sign of the reservoir. Water has begun backing up, slightly more penetrable to light as sediment settles out. In the next mile or so, the main current grows more elusive -- meandering through an expanding fringe of slow water. In evening light, I pull into a massive, tilted outcrop, the shore thick with soft, knee-high vegetation, weedy invasives, Russian thistle. Bats chitter around my head snatching up midges and mosquitoes. I lay my sleeping bag in the desert on top of red sand and sun-beached clamshells.

At dawn I pack up, unleash my boat from fresh spider webs, and move onto the water's gradual twist. Within a mile, I cannot count on much of a current. No more idle moments staring at the canyon: I need to pace myself with long strokes. I come upon random currents carrying sticks, seeds and little moons of rabbit pellets, but the reservoir grows. What was once a hill becomes an island. I navigate across floating cattail reeds, flower petals and Styrofoam, while grebes pop up and down, heads periscoping to watch me pass. Each time I think the river is gone, I find vestiges again. It rises and falls, as if it were tunneling deep below the surface, a submarine breaching, then descending through the murky vaults of Lake Powell.

I once spoke with a Park Service ranger who worked to recover the body of someone who drowned on this part of the river. She described floating particulate matter obliterating sunlight to a depth of 20 feet. Down deeper, the water became textured, viscous, until it felt like she was swimming through chocolate pudding.  Below 50 or 60 feet, the abyss of half-suspended mud felt like liquid concrete and it became hard to move, and for a moment she panicked, her fins trapped in the lightless tomb of mud where she had to unbuckle and extract them.

Here, the river's current may more or less disappear from the reservoir's surface, but the sediment it delivers keeps moving in the form of gravity flows, streamers of mud and silt slowly but inexorably advancing along the reservoir's floor toward the dam. In this fluctuating underworld, side-canyons dump their own sediment-deltas into the mainstem, forming subaqueous dams through which both San Juan River current and sediment carve their own channels. In the dark water far below, new canyons form within the sediment itself, and in places, walls of the original bedrock canyon have collapsed, forming dams where fine mudfalls spill over one after the next. "There are real small currents heavier than the rest of the water," explains Mark Anderson, head river ecologist for Glen Canyon National Recreation Area, who has been involved in mapping the underwater terrain of Lake Powell. "They are turbidity flows, not actually water, but they can roll down through the basin over a long period of time."

High Country News Classifieds
  • EXECUTIVE DIRECTOR
    Executive Director Position Announcement POSITION TITLE: Executive Director ORGANIZATION: Friends of Cascade-Siskiyou National Monument REPORTING TO: Board of Directors EMPLOYMENT TYPE: Part-time - Full-time, based...
  • HEALTHY CITIES PROGRAM DIRECTOR
    The Healthy Cities Program Director leads and manages the Healthy Cities Program for the Arizona Chapter and is responsible for developing and implementing innovative, high...
  • CONSERVATION PROGRAM MANAGER
    Grand Staircase Escalante Partners (GSEP) Conservation Programs Manager Job Opening Our Mission: Honoring the past and safeguarding the future of Grand Staircase-Escalante National Monument through...
  • ASSOCIATE DIRECTOR
    Grand Staircase Escalante Partners (GSEP) Associate Director Job Posting Our Mission: Honoring the past and safeguarding the future of Grand Staircase-Escalante National Monument through science,...
  • UNIQUE, ENERGY-EFFICIENT HOME ON ACREAGE NEAR MOSCOW, IDAHO
    Custom-built energy-efficient 3000 sqft two-story 3BR home, 900 sqft 1 BR accessory cottage above 2-car garage and large shop. Large horse barn. $1,200,000. See online...
  • OUTDOOR ADVENTURE BUSINESS FOR SALE
    Missoula Outdoor Learning Adventures (MOLA) - established and profitable outdoor adventure & education business in Missoula, Montana. Summer camp, raft & climb guide, teen travel,...
  • OJO SARCO FARM/HOME
    A wonderful country setting for a farm/work 1350s.f. frame home plus 1000 studio/workshop. 5 acres w fruit trees, an irrigation well, pasture and a small...
  • STEWARDSHIP COORDINATOR
    Join Skagit Land Trust (the Trust), a not-for-profit conservation organization based in Mount Vernon, Washington, and help protect land for people and wildlife. Skagit Land...
  • 2022 SEASONAL SCIENCE EDUCATOR
    The Mount St. Helens Institute Science Educator supports our science education and rental programs including day and overnight programs for youth ages 6-18, their families...
  • POLICY DIRECTOR
    Heart of the Rockies Initiative is seeking a Policy Director to lead and define policy efforts to advance our mission to keep working lands and...
  • CHIEF FINANCIAL OFFICER
    Self-Help Enterprises seeks an experienced and strategic CFO
  • CONSERVATION SPECIALIST - LAND PROTECTION FOCUS
    View full job description and how to apply at
  • RIVER EDUCATOR & GUIDE
    River Educator & Guide River Educator & Guide (Trip Leader) Non-exempt, Seasonal Position: Full-time OR part-time (early April through October; may be flexible with start/end...
  • LAND AND WATER CONSERVATION DIRECTOR
    The Land and Water Conservation Director is a full-time salaried position with the Mountain Area Land Trust in Evergreen, CO. The successful candidate will have...
  • FOOD SYSTEMS ENVIRONMENTAL FELLOWSHIP
    If you were to design a sustainable society from the ground up, it would look nothing like the contemporary United States. But what would it...
  • EXECUTIVE DIRECTOR
    The Rio Grande Headwaters Land Trust (RiGHT) is seeking an Executive Director who will lead RiGHT toward a future of continued high conservation impact, organizational...
  • COMMUNITY ORGANIZER
    Help protect Montana's water quality, family farms and ranches, & unique quality of life. Work hard, meet good people, make the world a better place!...
  • NEW BOOK:
    True Wildlife Tales From Boy to Man. Finding my voice to save wildlife in the Apache spirit. 365+ vivid colorful pictures. Buy on Amazon/John Wachholz
  • CHIEF OPERATIONS OFFICER
    with Rural Community Assistance Corporation. Apply here: https://www.marcumllp.com/executive-search/chief-operations-officer-rcac
  • CARPENTER WANTED
    CARPENTER WANTED. Come to Ketchikan and check out the Rainforest on the coast, Hike the shorelines, hug the big trees, watch deer in the muskeg...