Tuesday, December 9, 2014

Monday, October 6, 2014

Request for proposals

The SFPUC is requesting consultant proposals to provide as-needed river ecosystem science support for the Upper Tuolumne River Ecosystem Program. Details can be found on the SFPUC's website.

Wednesday, June 18, 2014

Rim Fire vegetation tracker

The Forest Carbon research team at NASA Ames Research Center has launched the Rim Fire Tracker online map viewer to help track regenerating vegetation areas within the 2013 burned severity classes.  The maps feature changes in current (2014) Landsat 8 NDVI (normalized difference vegetation index) compared to last October's (post-burn) NDVI.  The map layers will be updated every month with a new Landsat NDVI difference product.   Subsequent image analysis of the vegetation community in regenerating areas will be added to this map viewer over time. Tools are provided to zoom to a location, identify values, and download map layers.  Subsequent image analysis of the vegetation community in regenerating areas will be added based on the methods published previously by Potter et al. (2012).

Monday, April 14, 2014

Looking Downstream 2013 update

Yosemite National Park's 2013 update report for the "Looking Downstream" project is available for download in the library.

Draft O'Shaughnessy Dam Instream Flow Management Plan

The draft O'Shaughnessy Dam Instream Flow Management Plan is available for download via links provided below.  The plan is comprised of a main document (211 pp) and 13 technical appendices (619 pp).  The main document is intended to provide a thorough description of proposed future instream flow releases for O'Shaughnessy Dam and a summary of analyses used to develop the plan.  In-depth, discipline-specific technical descriptions of analytical methods and results are provided in the appendices document for more technical readers.

Main document (41 MB pdf)
Appendices (136 MB pdf)

Saturday, April 5, 2014

Tuolumne River whitewater access opens

Whitewater boating access for the Cherry and Lumsden runs on the Tuolumne River is open for the season.  Access is by shuttle only and free, mandatory permits are required via the Groveland Ranger Station.  For more information on white water and other recreation on the Stanislaus National Forest, see the Stanislaus National Forest recreation update.  Boaters are asked to watch for hazards associated with the Rim Fire such as landslides and fallen trees.

Friday, April 4, 2014

Wapama rockfall

Recent rockfall source area adjacent to
Wapama Falls (photo: Greg Stock, NPS)
A rockfall occurred just east of Wapama Falls on the North side of Hetch Hetchy Reservoir on March 31st, covering approximately 600 ft of the Wapama Falls trail.  The falls can still be reached from the west, but the trail is closed just east of the falls.  The National Park Service does not currently have an estimated date for reopening the closed section of trail.

Friday, March 28, 2014

Prescribed fire at Hetch Hetchy

Prescribed burn near O'Shaughnessy
Dam.  Photo courtesy of Yosemite
Fire Management.
National Park Service and US Forest Service fire crews completed a 57 acre prescribed fire near O'Shaughnessy Dam today.  The combination of recent rains, minimal snowpack, and slightly unsettled weather made for ideal prescribed fire conditions; these conditions typically don't exist in March due to snowpack and wet fuels. The fire treated vegetation and fuels around the buildings and other infrastructure near O’Shaughnessy Dam, and was designed to reduce surface and “ladder fuels” that allow ground fire to leap to the tree canopy and cause crown fires. The treated area will offer a “fuel break” for firefighters to safely protect structures at the O’Shaughnessy Dam.   The area burned with low intensity during the 2013 Rim Fire.

Thursday, March 27, 2014

Colorado River Delta re-watered by pulse flow

Seasonal high flow water releases, or pulse flows, are increasingly used to simulate natural hydrology and manage river habitats downstream of dams and diversions. Beginning March 23rd and continuing for eight weeks, about 1 percent of the Colorado River’s waters will be released into the Colorado River Delta in Mexico.  The release is part of a five-year pilot project designed to restore the delta environment and is part of an amendment to a decades old treaty between the United States and Mexico on management of Colorado River water.  Read more online.

Tuesday, January 21, 2014

Southern Sierra Fire and Hydroclimate Workshop

The first jointly scheduled Southern Sierra Fire and Yosemite Hydroclimate Workshop will be held April 22-24, 2014 in Yosemite Valley.  The workshop is focused on developing an integrated view of the physical landscape, climate effects, hydrology, and fire regimes of the Sierra Nevada.  This workshop was rescheduled from the original date back in October 2013 due to the federal government shutdown.  To register, visit the California Fire Science Consortium website.

Friday, January 17, 2014

November 2013 stakeholder meeting materials available

Presentations and other meetings materials from the November 15, 2013 Upper Tuolumne River Stakeholder Group meeting are now available here.

Tuesday, January 14, 2014

New USGS Ward's Ferry stream gage

The USGS has installed a new stream gage near Ward's Ferry Bridge, at the upstream end of Don Pedro Reservoir, to monitor Rim Fire-related water quality parameters.  The gage currently records stage, water temperature, conductance, turbidity, dissolved oxygen, and pH.  The gage is funded by Modesto and Turlock irrigation districts, and the SFPUC.

Friday, January 10, 2014

2011-2012 Yosemite "Looking Downstream" report available

Yosemite National Park's 2011-2012 update report for the "Looking Downstream" project is available for download in the library.  

Looking Downstream is a long-term interdisciplinary study designed to better understand the physical processes and ecology of the mainstem Tuolumne River between O’Shaughnessy Dam and the western boundary of Yosemite National Park, with a focus on the biologically diverse Poopenaut Valley.  The project provides critical information used to manage environmental water releases from O’Shaughnessy Dam.