Memory Lane

There’s a large-scale project under way to turn back the clock in order to better prepare for the future.

In Napa Valley, the non-profit San Francisco Estuary Institute (SFEI) has been working to establish the historical ecology of a region that has seen huge landscape use changes over the past two hundred years. It has gone from being from a massive estuary with varied ecosystems to a heavily populated stretch of land famous around the world for its wines, climate and culture.

It has also become less climate resistant and lost a great deal of biodiversity.

 A map, two aerial photos and a land survey showing different stages of the area around the Napa River and the city of Napa, Calif., in (from left) 1858, 1942, 2009 and 1858.  Composite by Ruth Askevold/San Francisco Estuary Institute; from left to right: National Oceanic and Atmospheric Administration, U.S.D.A., U.S.D.A., Courtesy of The Bancroft Library, University of California, Berkeley  Image/caption: New York Times

A map, two aerial photos and a land survey showing different stages of the area around the Napa River and the city of Napa, Calif., in (from left) 1858, 1942, 2009 and 1858.
Composite by Ruth Askevold/San Francisco Estuary Institute; (L to R) National Oceanic and Atmospheric Administration, U.S.D.A., U.S.D.A., Courtesy of The Bancroft Library, University of California, Berkeley
Image/caption: New York Times

The SFEI embarked on the task of establishing just how this key watershed once worked, in all its complexity.

Researchers dug deep into every kind of archive imaginable. From the SFEI site:

The Native Landscape View of the EcoAtlas is a composite picture based upon hundreds of independent sources of data. These include eighteenth- and nineteenth-century maps, sketches, paintings, photographs, engineering reports, oral histories, explorers’ journals, missionary texts, hunting magazines, interviews with living elders, and other sources.

Guadalcanal Mitigation Site, an area restored to tidal influence in 2001. Photo: Gena Lasko (CDFW)/SFEI

Guadalcanal Mitigation Site, an area restored to tidal influence in 2001.
Photo: Gena Lasko (CDFW)/SFEI

The goal isn’t so much to recreate the Napa Valley of the past as it once looked as it is to re-establish the estuary and ecology as they once functioned. To improve the once-lush delta to the point that it can better absorb both flooding as well as withstand drought.

A side effect is the return of some of the wildlife and plants that once lived where there are now vineyards, roads and suburbs.

It’s not as extreme as the de-extinction projects of long-gone animals like Revive and Restore, but it is an attempt to re-invent a future that looks, at least just a little bit, like what went before and was almost forgotten.

Tidal mud in Guadalcanal Mitigation Site. Photo: Sally Mack

Tidal mud in Guadalcanal Mitigation Site.
Photo: Sally Mack

Pulse Taking

‘Long memory’ is a term used in probability analysis. It originated in hydrology to predict flood patterns on the Nile River.

But do rivers remember where they once flowed?

Floraskin – Huth & Domenig Via: Data Is Nature

Floraskin – Huth & Domenig
Via: Data Is Nature

A large pulse of water was released along the Colorado River this year, an historic ecological undertaking meant to restore the once-lush downriver sections and delta. The goal of the 130 billion-liter (34 bn gallon) pulse was to imitate the spring floodwaters that once coursed the length of the river, but which have been diverted for other uses further upstream.

These images show the river before and after the water pulse was released. The river bed and tributary channels have been little more than dry markers for the memory of a river that once carried 18.5 trillion liters (4.9 trillion gallons) of water every year.

Before: An April 2013 view shows the dry river shell in northern Mexico. Credit: NASA Earth Observatory image by Robert Simmon, using Landsat 8 data from the U.S. Geological Survey

Before: An April 2013 view shows the dry river shell in northern Mexico.
Credit: NASA Earth Observatory image by Robert Simmon, using Landsat 8 data from the U.S. Geological Survey

After: Water flows through the same area, April 2014. Credit: NASA Earth Observatory image by Robert Simmon, using Landsat 8 data from the U.S. Geological Survey

After: Water flows through the same area, April 2014.
Credit: NASA Earth Observatory image by Robert Simmon, using Landsat 8 data from the U.S. Geological Survey

The final destination of the water is the Colorado Delta, which once formed a rich connection between the river and the Gulf of Mexico. The Delta has rarely seen river water since 1960.

As it turns out, the water pulse may not reach the Delta at all. Sand bars and shrubs are slowing the flow, even as conservationists work to re-establish trees and wetlands in its wake.

If there is such a thing, the long memory of the Colorado River may have to wait a while longer before it once again meets the Gulf of Mexico at the end of a long journey home.

 

http://www.livescience.com/45281-colorado-river-pulse-satellite.html

Transboundary Pulse

It’s a strange notion, the cutting off of water across an invisible territorial boundary. There are few actions we can take as humans – both for communities and for the environment – that are more baldly assertive than diverting rivers and water flow.

The Colorado River delta sits at the very end of the 2330 km-long (1450 m.) Colorado River, which winds southward from Colorado to the Sea of Cortez in Mexico. An object of human geo-engineering for hundreds of years, it’s only in the last century that the Colorado River became one of the most controlled, divided and litigated rivers in the world.

Over the past fifty years, so much water has been used in the United States that the river hasn’t reached the delta or the Sea of Cortez at all, turning what was once a lush system of lakes and marshes into a parched desert.

Collage of historical descriptions of the delta and an image of the dry delta of recent years. "The river enters the sea by a mouth four leagues wide...The Rio Colorado bathes (the land) like the Nile bathes Egypt, giving it great fertility." Source: Jordan Wirfs-Brock/

Collage of historical descriptions of the delta and an image of the dry delta of recent years. “The river enters the sea by a mouth four leagues wide…The Rio Colorado bathes (the land) like the Nile bathes Egypt, giving it great fertility.”
Source: Jordan Wirfs-Brock/Univ. of Colorado Boulder

But this week, for the first time in five decades and timed to coincide with World Water Day, water from the Colorado River flowed at more than a trickle on the southern side of the border in Mexico.

In 2012, the 1944 U.S.-Mexico treaty on river use was amended with an addition known as Minute 319, which aims to support reclamation of the delta through controlled ‘pulse flows’, large surges of water that then trickle off in an imitation of the pre-dam, pre-diversion river that flowed heavily with the snow melt in spring and tapered off through later months.

The surges created by this pilot project should help spread tree and plant seeds across the delta, while the tapering off should provide irrigation for plants to thrive. It’s hoped the influx of water and the re-establishment of plant life will also support the delta’s dwindling wildlife, including many species of migratory birds.

It’s an unusual cross-border project in that the water release isn’t specifically for commercial purposes, but to support environmental restoration.

Cross-border water cooperation and sharing to support ecosystem recovery: I suppose these days, that’s a strange notion, as well.

Colorado River Dry Delta, terminus of the Colorado River in the Sonoran Desert of Baja California and Sonora, Mexico, ending about 5 miles north of the Sea of Cortez (Gulf of California). Photo: Peter McBride USGS / Wikipedia

Colorado River Dry Delta, terminus of the Colorado River in the Sonoran Desert of Baja California and Sonora, Mexico, ending about 5 miles north of the Sea of Cortez (Gulf of California).
Photo: Peter McBride USGS / Wikipedia

Think of it as a surge of water. It’s what happens when there’s a big rainfall or the snow melts into a river. The flow increases for a few days or weeks, and then it goes back to normal. Rather than weather, this environmental experiment will be a release of water from a reservoir. It is designed to mimic the kind of natural pulse flows that help keep rivers healthy by spreading native plant seeds and creating conditions for those seedlings to grow and thrive. – See more at: http://www.nature.org/ourinitiatives/regions/northamerica/areas/coloradoriver/colorado-river-pulse-flow-qa-with-eloise-kendy.xml#sthash.2WwHpQtj.dpuf
Think of it as a surge of water. It’s what happens when there’s a big rainfall or the snow melts into a river. The flow increases for a few days or weeks, and then it goes back to normal. Rather than weather, this environmental experiment will be a release of water from a reservoir. It is designed to mimic the kind of natural pulse flows that help keep rivers healthy by spreading native plant seeds and creating conditions for those seedlings to grow and thrive. – See more at: http://www.nature.org/ourinitiatives/regions/northamerica/areas/coloradoriver/colorado-river-pulse-flow-qa-with-eloise-kendy.xml#sthash.2WwHpQtj.dpuf
Think of it as a surge of water. It’s what happens when there’s a big rainfall or the snow melts into a river. The flow increases for a few days or weeks, and then it goes back to normal. Rather than weather, this environmental experiment will be a release of water from a reservoir. It is designed to mimic the kind of natural pulse flows that help keep rivers healthy by spreading native plant seeds and creating conditions for those seedlings to grow and thrive. – See more at: http://www.nature.org/ourinitiatives/regions/northamerica/areas/coloradoriver/colorado-river-pulse-flow-qa-with-eloise-kendy.xml#sthash.2WwHpQtj.dpuf