University of Arizona dendrochronologists construct a 2,200 year chronology for the San Juan Mountains


From Science Daily:

The second century A.D. saw an extended dry period of more than 100 years characterized by a multi-decade drought lasting nearly 50 years, says a new study from scientists at the University of Arizona.

UA geoscientists Cody Routson, Connie Woodhouse and Jonathan Overpeck conducted a study of the southern San Juan Mountains in south-central Colorado. The region serves as a primary drainage site for the Rio Grande and San Juan rivers.

“These mountains are very important for both the San Juan River and the Rio Grande River,” said Routson, a doctoral candidate in the environmental studies laboratory of the UA’s department of geosciences and the primary author of the study, which is upcoming in Geophysical Research Letters…

To sample the trees without damaging them, the dendrochronologists used a tool like a metal screw that bores a tiny hole in the trunk of the tree and allows them to extract a sample, called a core. “We take a piece of wood about the size and shape of a pencil from the tree,” explained Routson.

“We also sampled dead wood that was lying about the land. We took our samples back to the lab where we used a visual, graphic technique to match where the annual growth patterns of the living trees overlap with the patterns in the dead wood. Once we have the pattern matched we measure the rings and average these values to generate a site chronology.”

“In our chronology for the south San Juan mountains we created a record that extends back 2,200 years,” said Routson. “It was pretty profound that we were able to get back that far.”[…]

“What we can see from our record is that it was a period of basically 50 consecutive years of below-average growth,” said Routson. “And that’s within a much broader period that extends from around 124 A.D. to 210 A.D. — about a 100-year-long period of dry conditions.”

“We’re showing that there are multiple extreme drought events that happened during our past in this region,” said Routson. “These megadroughts lasted for decades, which is much longer than our current drought. And the climatic events behind these previous dry periods are really similar to what we’re experiencing today.”

The prolonged drought in the 12th century and the newly discovered event in the second century A.D. may both have been influenced by warmer-than-average Northern Hemisphere temperatures, Routson said: “The limited records indicate there may have been similar La Nina-like background conditions in the tropical Pacific Ocean, which are known to influence modern drought, during the two periods.”

More coverage from the Associated Press via The Durango Herald. From the article:

The geoscientists said the San Juan River is a tributary for the Colorado River, meaning any climate changes that affect the San Juan drainage also likely would affect the Colorado River and its watershed.

Scientists say the prolonged drought in the 12th century and the newly discovered event in the second century may both have been influenced by warmer-than-average Northern Hemisphere temperatures. The researchers looked for indications of climate in the past in the growth rings of the oldest trees in the southern San Juan region to develop their chronology.

Click on the thumbnail graphic above and to the right for the current U.S. Drought Monitor graphic.

2012 Nonpoint Source Funding Cycle Announcement — Proposals Due January 13, 2012


From email from the Colorado Watershed Assembly:

The Water Quality Control Division, Nonpoint Source Management Area (NPS program) and its state water quality partners, the Nonpoint Source Alliance (Alliance) are now accepting proposals for projects to be considered for funding under Section 319(h) of the Clean Water Act.

The 2012 NPS Funding Cycle Announcement, with application forms, instructions, budget spreadsheet and other information is available at

PLEASE read all the information in the announcement and instructions before proceeding.

Mark your calendars! Proposals DUE January 13, 2012!

If you have any questions, contact a member of the CDPHE NPS Team by clicking here.

The NPS program staff will be available for consultation on proposal questions until November 30th. In the interest of fairness, pertinent questions will be posted in the Bulletin Board so that all proponents can access the information. After November 30th, staff will not answer proposal related questions and the consultation period will be finished. Proposals will be due on January 13th, 2012.

More water pollution coverage here.

Western Resource Advocates is pushing for better protection of groundwater with new state rulemaking process for hydraulic fracturing


A week or so ago the review of Colorado’s oil and gas production and exploration rules by the State Review of Oil & Natural Gas Environmental Regulations (STRONGER) was cited by the Colorado Oil and Gas Conservation Commission as part of their basis for a new rulemaking effort for hydraulic fracturing.

Here’s the release from Western Resource Advocates (Jason Bane):

Following the release of the Colorado Hydraulic Fracturing State Review, Western Resource Advocates is calling on Colorado Gov. John Hickenlooper to do more to protect Colorado’s citizens and water from the threat of fracking oil and gas wells.

A public-private committee dubbed STRONGER1 released an in-depth review2 of the Colorado hydraulic fracturing regulatory program on Friday, Oct. 28. The committee recognized several positive aspects of Colorado’s 2007 oil and gas rulemaking, but noted five specific areas of concern—most importantly the need to a) better protect groundwater quality, and b) to better understand where the industry will find the millions of gallons of water needed for fracking (and what that means for the environment and for other water users in Colorado).

The most significant piece of the STRONGER report is about what is not included. The report does not address Colorado’s draft disclosure rule for fracking chemicals; a proposal to allow the oil and gas industry to self-regulate on its FRAC-Focus website; or the need to increase residential setback requirements from the current minimum levels (150 feet for rural areas; 350 feet for urban areas). These issues are vital to ensure the safety of all Coloradans, regardless of where they live, and some need to be undertaken immediately.

“There is an urgent need to increase Colorado’s residential setbacks,” said Mike Chiropolos, Lands Program Director at Western Resource Advocates (WRA). “The single most important thing that Colorado can do to protect homeowners in the gas patch is to increase the distance between drilling rigs and our homes.”

There are currently 45,000 active oil and gas wells in Colorado, and more than 5,000 new permits were approved in 2010 alone. The STRONGER report will help set the stage for potential reforms and regulations of fracking in 2012.

More coverage from David O. Williams writing for the Colorado Independent. From the article:

Dubbed the Colorado Hydraulic Fracturing State Review (pdf), the independent private-public review had been cited by some observers as a possible impetus for Gov. John Hickenlooper somewhat reluctantly agreeing this summer that the state oil and gas regulatory agency should draft a public disclosure rule for fracking chemicals.

That rulemaking process by the Colorado Oil and Gas Conservation Commission (COGCC) is under way, with a draft disclosure rule scheduled to be released and published in the Colorado Register (pdf) on Nov. 10. Hearings are slated for December, and COGCC regulators hope to have a rule finalized by the end of the year.

One of the revised rules Colorado adopted in 2008 after a long and contentious rulemaking process was a regulation requiring companies to keep an inventory of chemicals onsite during drilling and fracking operations and make that inventory available to regulators and healthcare professionals upon request.

“This rule allows government officials and medical professionals to investigate and address allegations of chemical contamination associated with hydraulic fracturing, while protecting proprietary information,” the STRONGER report states.

But the report went on to raise concerns about water supplies for fracking (up to a million gallons per well) and recommended a comprehensive state evaluation of available water resources as they related to fracking operations, which occur in about 90 percent of natural gas wells.

“Given the significant water supply issues in this arid region, this project should also include an evaluation of whether or not availability of water for hydraulic fracturing is an issue and, in the event that water supply is an issue, how best to maximize water reuse and recycling for oil and gas hydraulic fracturing,” the report states in its executive summary.

More oil and gas coverage here and here.