News & Operations Blog

Folsom Temperature Shutter Change

Posted on Thursday, August 9th, 2018


The following Folsom Dam Temperature Shutter Change Order was issued by Peggy Manza on 8/9/18:

Project: Folsom Dam

Please put Unit 3 in configuration 2 at approx 7:30 am on Thursday, August 9, 2018.

Configuration after changes:

Upper shutters – Units 1, 2, and 3 up

Middle shutters – all down

Lower shutters – all down

Comment: Temperature management in the Lower American River

Ordered by:  Peggy Manza

Change Order

Posted on Wednesday, August 8th, 2018

The following change order was issued by Peggy Manza on 8/7/18:

Please make the following release changes to the American River at Nimbus:

Date         Time    From (cfs)      To (cfs)

8/09/18       2100      4,500            4,400

8/09/18       2200      4,400            4,300

8/09/18       2300      4,300            4,200

8/10/18       0000      4,200            4,100

8/10/18       0100      4,100            4,000

Comment:  Reduced delta needs

New residents at Cordova Creek

Posted on Thursday, August 2nd, 2018

New Residents at Cordova Creek

Overview of Cordova Creek in July 2018

If you have recently strolled through Cordova Creek, you may (or maybe not) have noticed new additions to the creek – beaver dams! On the one hand, this is an exciting indicator of the successful naturalization of the area, as native species continue to utilize the site and make it their home! Though beavers provide numerous ecological benefits –like increasing biodiversity, preventing downstream flooding, and minimizing pollutants – they can also simultaneously cause problems in urban environments, commonly referred to as human-wildlife conflict.

Our CivicSpark Fellow Cassie has worked diligently to find a solution to balance the needs of the beaver with the successful establishment of the creek.

Left: Beaver dam creating a pond ecosystem Right: The pond leveler installed and managing pond dimensions

As the ubiquitous population of North American beavers (Castor canadensis) has steadily recovered from historic depletion, it has become increasingly apparent that these aquatic mammals can fundamentally modify existing hydrologic regimes. Due to this ability to change their environment, beavers have earned the status and nickname of ecosystem engineers. In natural environments, their engineering abilities can be incredibly beneficial.

However, the initial dam on Cordova Creek had detrimental impacts on the newly naturalized site. The beaver dam caused nearby banks to submerge, which in turn caused the drowning of young plants and it began to overflow across the trail. Additionally, the beaver removed cottonwood trees, young willows, and many yards of irrigation which cascaded into many more plant problems.

Though the damage caused by the beaver was not easy to ignore, we recognized that it would be unreasonable to get mad at a beaver for simply doing what beavers do. Thus, we brainstormed ways to live peacefully with the beaver, while continuing to maintain the site in its early years of establishment. Through the help of Sacramento-Yolo Mosquito & Vector Control District, a pond leveler was installed on the creek. The pond leveler is a pipe that goes through the dam to allow a certain amount of water to pass through the dam whilst maintaining a pond environment for the beaver.

Additionally, through the help of Soil Born Farms, their summer high school interns spent a morning on Cordova Creek assisting in wrapping vulnerable cottonwood trees with fencing to protect the trees from beaver herbivory. Cottonwood trees have slower growth rates compared to willows which will naturally recover faster from beaver herbivory. Now that the cottonwoods will have a chance to grow, they will be able to provide some shade to the many walkers, runners, and cyclists enjoying the trail.

Left: Student interns prepare to wrap a cottonwood tree Right: Student interns pose and smile after wrapping 15 cottonwood trees

As Cordova Creek continues to establish itself, we look forward to welcoming new wildlife residents to the neighborhood and finding innovative ways to resolve any more human-wildlife conflicts that may arise.

Fires & Opperations

Posted on Monday, July 30th, 2018

Date: Fri, Jul 27, 2018 at 11:43 AM

ARG members.  As you may be aware from recent news reports, the Carr fire in northern California is currently affecting operations of all our Northern facilities.  Shasta and Keswick were both evacuated last night.  Powerline transmissions have been impacted.  CVO is currently in emergency operations mode.  While Folsom Reservoir is obviously not in the direct line of fire, as a coordinated project, there may be some temporary operational changes at Folsom, mostly relating to power generation.  It is hoped that the situation will be stabilized by next week and we can reassess project operations across all projects at that time.

Thank you for your understanding, and I will update you as new information is available.

Peggy Manza

Change Order

Posted on Monday, July 2nd, 2018

Date: Mon, Jul 2, 2018 at 9:19 AM
Subject: Nimbus Dam – Change Order

Please make the following release changes to the American River at Nimbus:

Date         Time    From (cfs)      To (cfs)

7/05/18       0800      4,500            5,000

Comment:  Delta needs

Issued by: Peggy Manza

Change Order

Posted on Friday, June 29th, 2018

Date: Thu, Jun 28, 2018 at 9:29 AM
Subject: Nimbus Dam – Change Order

Please make the following release changes to the American River at Nimbus:

Date         Time    From (cfs)      To (cfs)

7/02/18       0800      4,000            4,500

Comment:  Delta needs

Issued by: Peggy Manza

Managing Cordova Creek: Staying ahead of Star Thistle

A native to Mediterranean Europe, the yellow star thistle (Centaurea solstitialis) made its way to California during the mid-19th century, likely via Chile through contaminated alfalfa mixes. With the lack of natural herbivores, the star thistle has the ability to create monotypic stands along disturbed landscapes. Their voracious nature eliminates and prevents other plants from growing, which degrades ecosystems and acts as a physical barrier for animal and human movement in wild spaces. Currently, it is estimated that star thistle occupies over 15 million acres of California’s floristic zone, and Cordova Creek, along with the American River Parkway, is no exception.

An unseasonably wet winter ‘16-17, hot summer, and the recently disturbed soil from Cordova Creek’s construction, all aligned to create an ideal habitat for star thistle to thrive in. As a result, the population exploded to an unprecedented level that the Water Forum and our partners were unprepared to fully manage. However, we are using the knowledge that we learned from last year’s experience to guide our current management strategies.

Starting in April, work crews have diligently hand-pulled and removed thousands of young star thistle growing throughout Cordova Creek. Despite their hard work, star thistle persistently exists in a few problem areas. To help address these problem areas, the Cordova Recreation & Park District,  Soil Born Farms, and the American River Flood Control District kindly agreed to each donate a day of mowing at Cordova Creek. Mowing star thistle can be extremely effective as a removal technique if timed correctly – once the plants have matured, bolted, and are at ~10% flowering. Mowing during this critical period prevents seeds from developing, and, without rain, the plants will be unable to regrow and flower this season.

We appreciate the help of Cordova Parks and Recreation, Soil Born Farms, and the American River Flood Control District as we manage and control star thistle. We are confident that the combined efforts will ensure the success of Cordova Creek and the immense amount of ecosystem services that it provides to the community!

For more information on how to manage star thistle in your own area: Yellow Star Thistle Management Guide