You are hereHeadwaters and Tributaries
Headwaters and Tributaries
The headwaters of the San Joaquin River provide clean water, beautiful scenic vistas, and opportunities to discover your place in the natural world. These high Sierras are not without problems; impacts of a changing climate, human activity, and airborne pollution all present threats that need to be addressed. The Upper San Joaquin, the Fresno, Chowchilla, Merced, Tuolumne, Stanislaus, and Calaveras Rivers all feed into the mainstem of the San Joaquin creating the second largest river in California.
The GEOS Institute issued a DWR funded report “Future Climate, Hydrology, Vegetation, and Wildfire Projections for the Southern Sierra Nevada, California” in May 2014. This was the first information I have seen integrating global and local models into basic climate change data for our watersheds in the San Joaquin Valley. The data provided is significant to all Californians and should be reviewed and understood by water managers throughout the State. Planning today can help us to identify our vulnerabilities and strategies for adaptation to the changes that are already occurring. The term “Irreversible Climate Change” identifies that there are positive feedbacks in our climate system that kick in to such an extent that emission reductions are no longer effective.
The early data released in this report is shocking! Using widely accepted climate models, and integrating these projections with local hydrology data, we begin to see a range of possible or likely changes in our hydrologic system. The report emphasized how dominant evapotranspiration rates were to the potential for hydrologic change (changes in precipitation do not translate directly to changes in water supply). The following represent some standout data released under the ‘business as usual’ climate projections for Southern Sierra:
- Changes to Sierra Nevada hydrology are already occurring (15.8% declines in snow water equivalents, increased wildfires, 16% increase in frequency and intensity of very heavy precipitation, spring runoff occurring 1 to 3 weeks earlier)
- Increase in average annual temperature of up to 4.1 degrees Celsius by 2099 (up to 11 degrees Fahrenheit in Summer months)
- An average of 75% reduced runoff in Summer months (May through September, and reaching up to 95%-97% reduction in late summer)
- Broad agreement in models of 82% - 86% reduction in annual average snowpack
The report emphasized that the resource models we use today can no longer rely on historic data anticipate future conditions. We
North County Times-5/17/10
By Jeff Barnard -- Associated press
The U.S. Environmental Protection Agency said Monday it will impose restrictions on spraying three agricultural pesticides to keep them out of salmon streams after manufacturers refused to adopt the limits voluntarily.
EPA will develop new rules for applying the chemicals diazinon, malathion and chlorpyrifos that will include no-spray zones along streams and restrictions on spraying depending on weather conditions, EPA spokesman Dale Kemery said in an e-mail.
The San Joaquin River is all over the news these days, thanks to long-awaited restorative flows.
Published online on Thursday, Oct. 01, 2009
By Marek Warszawski / The Fresno Bee
Well, here's a San Joaquin River story that hasn't gotten much attention - unless you're plugged into the expedition kayaking community.
An editorial appeared in the Fresno Bee today highlighting the dangers of dredge mining in California’s rivers and the environmental harm it causes along with harm to jobs and the economy.
Dredge mining in rivers does several harmful things: 1) It mixes up and returns potentially toxic material to the river flow. (Many rivers in California have mercury from gold mining in the 1800’s that have been embedded deeper into the sediment.) 2) The murky sediment returned to the rivers from the dredging makes swimming hazardous and unhealthy. 3) The disturbance of the river bottom also disturbs fish laying eggs. In particular salmon which lays eggs in the gravel bottom and young lamprey that can reside in gravel for up to seven years before maturing.