Wednesday, April 29, 2020

Elwah steelhead success story

More good news from the Elwah River...  An article in Northwest Sportsman reveals the incredible resilience of the steelhead which have rebounded faster than predicted following the removal of two dams on the Elwah River in Washington State.  The video, "Rising from the Ashes" tells the story from the perspective of the dedicated biologists and volunteers who have undertaken annual snorkel surveys on the remote and hard to access river in the wilderness of the Olympic National Park.

The rapid recovery of the summer steelhead on the Elwah demonstrate the value of resident rainbow trout above dams.  Given the chance, even after 100 years with no possibility of returning from the ocean, these fish can make a comeback.

This is real world confirmation of the hope for recovering the endangered southern steelhead populations blocked by Matilija Dam.  With no human intervention, other than just getting out of the way, we can realize a rapid recovery of the native fish and the ecosystem on which we all rely.

New Film Highlights Elwha Summer-runs ‘Rising From The Ashes’, Northwest Sportsman, April 23, 2020

On this blog: steelhead

Thursday, April 16, 2020

Ecosystem flows

Natural flows in rivers throughout the American West have been significantly disrupted by dams and diversions, groundwater extraction, land use changes, and other human influences.  Over time this has led to the decline of freshwater ecosystems to the point that many species have become endangered.  For instance, rivers rely on natural floods for maintenance of the river channel and floodplain, and flow of critical nutrients and biota.  Large dams mute or eliminate downstream flooding (winter flood pulses) by capturing these flows in a reservoir.  Similarly most western rivers are drying up during the dry months (summer/early fall base flows), an increasing concern with more frequent drought and heat due to climate change, and the primary concern on the Ventura River.

Functional Flows, figure from "A Path Forward for California's Fresh Water Ecosystems", PPIC 2019

The diagram shown here illustrates alterations to the natural flow regime throughout the year and a proposed "Functional flow regime."  The aim of functional flows is to re-establish some of the basic river functions in highly modified systems to restore ecosystem function.

The question is how to develop a management paradigm to allocate water to functional flows and ecosystem health?

A recent report by the Public Policy Institute of California presents the case for Ecosystem Based Management as a solution to California's water problems.  Maven's Notebook presents an excellent summary of recent discussions along with the technical references.

In particular, this report concludes that the current management focus on endangered species is failing, and we need a more holistic approach:

Ecosystem-based management emphasizes the simultaneous management of water, land, and species to improve ecosystem condition for native biodiversity and human uses. It shifts the management emphasis to the social, economic, and environmental benefits that come from healthy ecosystems, rather than narrowly focusing on mitigating harm to protected species.

Sustainable watershed management plans, backed by binding comprehensive agreements, are the best way to accomplish ecosystem-based management. These agreements can be adopted by state and federal regulators to meet Clean Water Act and ESA requirements and can align other agency priorities and actions.

With ecosystem-based management, there are a suite of actions available.  The first is to establish an ecosystem water budget that is an allocation of water for the environment that functions much like a senior water right that can store, trade, and flexibly allocate that water to respond to changing conditions.

An outline of this management approach is presented in the PPIC Policy Recommendations:

Promote inclusive planning and governance

  • Identify the desired ecosystem condition
  • Establish metrics
  • Provide strong scientific support
  • Set up transparent governance
  • Ensure reliable funding

Employ multiple ecosystem management tools
  • Establish ecosystem water budgets
  • Employ functional flows
  • Manage native and non-native species
  • Manage at the appropriate scale

Encourage sustainable watershed management plans
  • Align agency actions
  • Promote comprehensive agreements
  • Set timelines and backstops
  • Update water quality control plans
  • Incentivize or mandate plans

It is important to highlight the differences between ecosystem-based management and other, often similar approaches. For example, 

      * ecosystem management seeks to manage the ecosystem for species conservation goals and objectives, such as resilient populations of native plants and animals. This is accomplished principally by constraining land and water use and often uses recovery of protected species as a primary objective. In contrast, 

      * ecosystem-based management integrates human uses into the setting of conservation goals and objectives, balancing the uses of the resource. Ecosystem-based management also differs from 

      * Integrated Water Resources Management (IWRM), which focuses principally on coordination and funding of local water management projects while managing their impacts on ecosystems.

Renewed discussion of Ecosystem-based Management supports the vision presented in the Ventura River Ecosystem blog.  This approach applies readily to the Ventura River Watershed, especially with ongoing planning for this priority basin under SGMA.  The Sustainable Groundwater Management Act provides for self-organized groundwater sustainability agencies (GSAs) and required groundwater sustainability plans.  However, in our case the Ventura River would ideally combine the two existing GSA's into a single watershed-based agency to better realize the Ecosystem-based management approach.

On this blog:

Ventura River; Ecosystem-based Management


text in italics above quoted from: 

Mavens Notebook: Ecosystem-based Management: A New Paradigm for Managing California's Freshwater Ecosystems

A Path Forward for California’s Freshwater Ecosystems, PPIC Water Policy Center, December 2019

More information:


Sunday, April 5, 2020

March rains

March storm moves over the Ojai Valley. This thunderstorm produced a brief period of hail.

After, a record dry January and February, the rains returned in March.  Perhaps not the "March miracle" of the past, but certainly appreciated given the potential for an otherwise very dry year.  At 13" for the season, Ojai is still way below the 23" average rainfall, but it looks like a wet spring ahead.

28 day Rainfall Map, March 2020

The storm of March 11 delivered almost 5 inches at Old Man Mountain, which typically registers the highest rainfall in the region.  Old Man Mountain lies at the headwaters of Matilija Creek, resulting in quickly rising waters during a downpour.  

24 hour rainfall, March 16, 2020
The hydrograph below shows flows in the river for the month of March at Matilija Creek and Foster Park.  The March 16th rain event resulted in peak flows for the season.

Ventura River above Hwy 150,  5pm
March 16, 2020

Ventura River at Santa Ana bridge,  6pm
March 16, 2020

This short burst of energy in the river moved significant amounts of sand and gravel sized sediment downstream.  In addition to visible deposition in Matilija reservoir, sedimentation was evident at Robles diversion and the reach downstream in the Ventura River Preserve.   Gravel is an important habitat consideration for the endangered steelhead, which lay eggs in "redds", or pockets formed in the gravel.  The effects of the Thomas Fire continue to be evident as the river transports sediment eroded from the mountains downstream, to the benefit of riverine habitat. 

Robles Diversion dam, March 19, 2020
Ventura River downstream of Robles Diversion, gravel bars, March 19, 2020
Ventura River Preserve, March 21, 2020

Ventura River Preserve, April 1, 2020

Flows in the river were also translated into rising groundwater at the Ventura River Water District wells and increased storage in Lake Casitas.

Water Supply, Courtesy of Ventura River Water District
April 1, 2020

At time of writing the watershed is preparing for another potentially significant storm and more rainfall for the week of April 5.

On this blog:
Matilija Reservoir March 2020
Steelhead spawning surveys
Thomas Fire

Ventura County Rainfall map
Casitas Municipal Water District
Ventura River Water District