Friday, October 23, 2020

Mondos Cove Stairway Preliminary Design

On Oct 21, 2020, BEACON presented a concept for improved beach access at the popular "Mondos Cove." The preliminary plan illustrates a new concrete stairway to provide access over the boulder riprap shoreline down to the beach.





The following are comments submitted on behalf of the Ventura County Chapter of the Surfrider Foundation:

RE: Mondos Cove Public Beach Access Stairway Preliminary Design 

Dear Marc,

Thanks for your presentation on the preliminary design concept for improving beach access at Mondos Cove beach along Old Pacific Coast Highway in Ventura County. The gentle waves at this popular beach have introduced surfing to many residents and visitors, but parking along the busy highway and access to the sand over the boulder riprap can be hazardous, especially for families with small children. Surfrider supports the efforts of BEACON to improve beach access at Mondos Cove. Please consider the following comments as you advance this important project:

Other locations should be considered for the crosswalk and stairs. The current proposal places foot traffic at the narrowest part of the highway and potentially creates a safety hazard for families waiting to cross the highway with small children, bulky beach gear, and surfboards. Safety may be improved by moving the stairway a short distance to the southeast, or providing two separate crosswalks.

The current stairway design encroaches onto the beach. Constructing stairs in the manner shown will expose the structure to unnecessary damage during winter storms. During periods of high waves waves break on the boulder revetment and there is very little sandy beach. As witnessed elsewhere in the county, wave action and impact from cobblestone and other debris will erode the proposed concrete stairway. As currently drawn, the bottom few stairs are particularly vulnerable. This situation will only worsen with rising sea levels. (See https://www.venturariver.org/2010/07/ventura-promenade-repairs.html)

Consider building the stairs parallel to the road so they are protected by a wall on the ocean side - ideally the whole structure would be within the footprint of the existing riprap. The Coastal Commission may require this as part of their permitting process. The structure will last longer with a parallel configuration, and this is what most of the private stairways look like along adjacent Pitas Point. (see attached sketch and photo)

Sketch (in red) showing alternative stairway alignment to avoid beach encroachment and minimize future damage



Aerial view of parallel stairway alignments along Pitas Point

Stairway design may be optimized by adjusting the rise and run. The current design shows 6” risers, which results in a lot of stairs and a long run. Depending on applicable code, stair rise could be increased to 7” or 8” (IRC (International Residential Code) calls for a maximum rise of 7 3⁄4”.) This would make the length of the stairs more compact, but a bit steeper.

Other materials should be considered. Given the uncertainty of future planning and accommodation for sea level rise, a simple timber stairway (or two) installed over the riprap may serve to enhance beach access for the next decade or more. This may be a cheaper and easier alternative to provide a short- to medium-term solution. Many of the adjacent homeowners have wooden accessways that seem to be quite durable.

ADA option should also include stairs. If an ADA ramp is desired, stairs should also be included. The accessway constructed with the recent seawall reconstruction down the coast did not include stairs, and the long switchbacking slope of the ADA ramp is awkward.

Consider long term planning for the site. An integrated plan should be considered to include parking, traffic control, protection of utilities, as well as beach access. For example, a seawall may be needed in the future to protect the highway and extensive utility lines on the ocean side of the street. Parking should be improved to provide a safer, cleaner environment. Signage and speed bumps or other traffic calming measures should be considered to slow traffic through this high use area. Whatever is built now should be able to accommodate future changes.

Develop an alternatives analysis. Given the limited budget for constructing improved beach access at this site, other conceptual alternatives should be developed considering the suggestions above with cost estimates in order to determine the best course of action.

Surfrider has consistently advocated for improved safety and access at Mondos Cove beach for the past two decades. We appreciate this new initiative and look forward to working with BEACON on developing a cost effective and timely solution to this important concern for all beachgoers.

Wednesday, October 7, 2020

Beavers


There has been a considerable amount of scientific and on-the-ground research since the previous post on Re-Beavification.  This topic was met with tremendous skepticism, and outright scorn from some during the development of the Ventura River Watershed Plan.  However, new information lends credence to the idea that re-introduction of beaver to the watershed could provide significant benefits and even resolve some of the ongoing conflict over water supply.

There is a growing understanding of the concept of "slow it, spread it, sink it" as a tool in protecting and improving groundwater resources.   In general this applies to our land management practices, where shifting away from impervious "pave it and drain it" practices helps put water back in the ground.  But just as important, we should consider how past changes in our rivers and creeks have also impacted the amount of water stored underground.  

In this video, National Forest hydrologist Kami Elison explains the benefits of "Living with Beaver"


 

Are Beavers native to the Ventura River?

Many do not realize that before the "Gold Rush" trappers scoured every nook and cranny of the state during the "California Fur Rush."  Of course the nearby Channel Islands was a treasure trove of fur seals and sea otters, but trappers also went up the rivers for beaver.  This is described in this wikipedia article on the history of beavers in California.  As part of their Bring Back the Beaver CampaignKate Lundquist and Brock Dolman co-authored The Historical Range of Beaver in Coastal California, a peer-reviewed scientific paper re-evaluating the historic evidence of beaver on the coast of California. Ventura County is included in this research.

Why are Beavers important?

Beavers are nature's engineer, and their removal from our coastal rivers had a drastic effect on the ecosystem.  North American beaver (Castor canadensis) are what biologists call a “keystone species” as the habitat they create benefits many other species. Their dams improve water quantity and quality, increase late season flow and reduce the impacts of flooding. Beaver bank burrows and food caches provide critical habitat for many native and endangered California species. 

Here is what the Water Institute of the Occidental Art and Ecology Center has to say:

“Extensive research has recently heightened recognition of the important role beaver (Castor canadensis) can play in watershed health and climate change resiliency. The species’ ecological services include enhanced water storage, erosion control, habitat restoration and creation, listed species recovery, the maintenance of stream flows during the dry summer period, and other beneficial adaptations to our changing climate conditions."

Despite these benefits, current California beaver policy solely focuses on recreational hunting and lethal nuisance management. In response, the WATER Institute launched a Bring Back the Beaver Campaign to educate citizens about the importance of beaver. In order to improve water supply for humans and the environment and increase resilience to drought and climate change, we are working to integrate their management into California policy and regulation.

In addition to the resources on OAEC's site, the Beaver Institute has a large library of technical reference on everything from biodiversity and climate change, to experiments with man-made "Beaver Dam Analogs" that have been demonstrated to restore streams.  

Interestingly, visitors to the Ventura River have shown a tireless propensity for building pools in which to cool off in the hot months.  These human dams may in fact be a form of Beaver Dam Analog, slowing the flow, and perhaps even helping to increase our precious groundwater supply. 

Ventura River "Beaver Dam Analog" (BDA)


Below is a list of references and articles for those interested in learning more:

Bring Back the BeaverOccidental Art and Ecology Center

Beaver Institute

Keep Me Wild: Beaver:  California Department of Fish and Wildlife 

 'We became beavers' US Fish and Wildlife Service Partnering with the Scott River Watershed Council, designed a project to simulate what beavers had not been around to do for decades

Role of Beaver in Stream Ecosystems: Overview of beaver life history and habitat requirements, presentation from NOAA Northwest Fisheries Science Center

Why Beavers are Worth a Dam!  Environmental Protection Information Center (EPIC) advocates for statewide beaver relocation program

Beavers—Once Nearly Extinct—Could Help Fight Climate Change National Geographic; Beaver ponds keep rivers and streams wet all year, compensating for less snowpack and glacial melt. We just need to stay out of their way.

The Bountiful Benefits Of Bringing Back The Beavers, NPR Weekend Edition

Bring Back The Beavers  article includes video "How Beavers Engineer the Land" 

The Martinez Beavers: Worth A Dam



Friday, September 18, 2020

Channelkeeper and Ventura Settlement Agreement


from the press release of August 24, 2020:

 Channelkeeper and the City of Ventura Amend Settlement Agreement 

The City of San Buenaventura and Santa Barbara Channelkeeper, a local environmental group, have announced an amendment to their settlement agreement in the lawsuit regarding the pumping and diversion of water from the Ventura River Watershed. Both Channelkeeper and the City remain committed to ensuring the protection of this local water source and the species that rely on it. The ongoing collaboration enables dialogue toward a locally developed solution to continue moving forward.

Under the modified terms, the City will continue the Pilot Program it implemented in 2019 to reduce its pumping and diversion of water from the Ventura River when flows drop during dry times, in order to help protect wildlife that depend on the river. The Pilot Program was originally set to expire in March of 2020, however, the City continues to honor the flow regime set in place. The most notable change with the amendment is that the City will shut down most of its pumping facilities at Foster Park when flows drop below 4 cubic feet per second (CFS), and stop all production when flows drop below 3 CFS instead of 2 CFS. The City will also use its two new gauges at Foster Park to monitor the impacts, if any, its pumping has on flow in the river at these levels.

Additionally, the City and Channelkeeper have agreed to keep a dialogue open to identify additional ways to work collaboratively on other Watershed and habitat-related public relations efforts.

“We are pleased to continue this important dialogue with Channelkeeper, and I believe this amendment strikes a balance of addressing our concerns for the species and habitat while also meeting the needs of serving our customers,” said Susan Rungren, Ventura Water’s General Manager.

This is a meaningful commitment to preserve river flows until a long-term solution is finalized, and we are glad to have been able to reach it through dialogue with the City,” said Ben Pitterle, Channelkeeper’s Science and Policy Director. The original agreement and this amendment provide added assurance to Channelkeeper for the better protection of steelhead during the dry season while the City works with other parties to propose a long-term framework that protects the Ventura River for steelhead and other instream uses and for the needs of water users, recreation, and the local economy.


In the news:

VENTURA, CHANNELKEEPER ANNOUNCE SETTLEMENT | CITY TO MONITOR FLOWS AND CONTROL PUMPING, VC Reporter, Sep 2, 2020

Ventura, Channelkeeper modify settlement agreement, Ojai Valley News, Aug 24, 2020



On this blog:

ChannelKeeper sues to save a drying river

ChannelKeeper settlement on City's pumping

Ventura Initiates Adjudication 

Tuesday, September 8, 2020

Ventura sues for indigenous water rights

More than 6 months after the City of Ventura served notices on all water rights holders in the Ventura River watershed, notices were served to the local Chumash tribal elders.  

(courtesy Ojai Valley News)

A response was published in the Ojai Valley News:

 July 10, 2020, the City of Ventura served papers on the Chumash tribal leaders, as a California Native American tribe: the Barbareño/Ventureño Band of Mission Indians, telling them their rights are subordinate to the City. All Chumash, the indigenous people, are being diminished, dismissed and insulted by the City’s assertion of Pueblo-misson rights.

On July 23, in response to nationwide and local protests, the City of Ventura removed a statue of Junípero Serra, the founder of Mission San Buenaventura.  According to the LA Times:

Serra was the founder of nine of 21 missionaries in California during the 18th century.  While he spread Roman Catholicism throughout much of California, then a Spanish territory, many Native American tribes were decimated through the introduction of foreign diseases, the destruction of villages and native plants and animals.  Natives Americans also were forced into the construction of the missions, faced high death rates and were subjected to harsh corporal punishment.


https://en.wikipedia.org/wiki/Father_Serra_statue)



 The response to the City's lawsuit continues:

It is hypocritical of the City of Ventura in one act to vote to remove the Serra statue and on the other to assert that the city’s water rights somehow, outrageously, supersede the rights of our land’s first inhabitants. The lawsuit’s claims undermine their own values. Where is the truth and dignity of the Ventura City Council members?

 

On this blog:

Tuesday, September 1, 2020

Economic Benefits of Dam Removal

An report published by the Bay Area Council Economic Institute outlines the economic benefits of the Matilija Dam Ecosystem Restoration Project.

from the website

... A valued forum for stakeholder engagement and a respected source of information and fact-based analysis, the Institute is a trusted partner and advisor to both business leaders and government officials. Through its economic and policy research and its many partnerships, the Institute addresses major factors impacting the competitiveness, economic development and quality of life of the region and the state, including infrastructure, globalization, science and technology, and health policy. 



An example of their analysis is summarized in the table below.  Note the multiple project components of the watershed-scale effort to remove Matilija Dam and restore the Ventura River ecosystem.


The full report may be downloaded here:  http://www.bayareaeconomy.org/report/job-stimulus-matilija-dam-removal/


Monday, August 24, 2020

Casitas Draft Comprehensive Water Resources Plan


Comments on DRAFT CASITAS MUNICIPAL WATER DISTRICT COMPREHENSIVE WATER RESOURCES PLAN (CWRP 2020), Submitted by Surfrider Foundation, 8/24/2020

Casitas Municipal Water District is developing a Comprehensive Water Resources Plan (CWRP) to provide information to guide future management of our water supply. The draft document currently recommends almost $160 million in capital projects, most of which is dedicated to the pursuit of imported water from the State Water Project. The fiscal impact to the ratepayer is left for future work. However, although it is not highlighted in the document, the CWRP clearly demonstrates the community’s ongoing response to changing conditions, and the very real capacity for sustaining our local water supply without the cost of imported water.


Updated Models:

The Draft CWRP document contains valuable information on water demand and supply for the largest water district in the Ojai Valley. The updated Lake Casitas Yield Model estimates that the safe yield from Lake Casitas has been reduced by 15% since the 2004 model. This is primarily a result of lake sedimentation, changes to the Robles Diversion, and the impacts of a changing climate. SAFE YIELD is defined as the largest amount of water that can be drawn from Lake Casitas every year in the period of record, without storage dropping below the minimum allowable storage level.

However, the good news is that the actual demand for water has declined to match the changing conditions. Reduced demand is to some degree a result of the policies developed in the Water Efficiency and Allocation Program (WEAP, 2019), which reduce customer allocations according to the lake storage. Incorporating this demand reduction into the Lake Casitas Yield Model results in the more realistic concept of “Safe Demand.”

Safe Demand is the largest amount of water that can be drawn from Lake Casitas every year in the period of record when demand is reduced based on Lake level according to the WEAP policy. - CWMP

The updated Lake Casitas Yield Model now accounts for the demonstrated reductions in water consumption during drought periods. When accounting for climate change, the projected “Safe Demand” of 10,700 AFY on Lake Casitas is approximately half of the assumed Safe Yield, yet this is well within the range of current water use. In fact, according to the CMWD website, current lake demand is 7,381 AFY, reflecting more than 30% conservation of Safe Demand as recommended by the WEAP during stage 3 drought. Therefore, according to the updated modeling presented in the draft CWMP, the community is well on the path to sustainable use of Lake Casitas.



Risk Assessment:

Rather than build upon this favorable conservation trend, the CWRP inflates the projected demand on Lake Casitas in a risk assessment designed to demonstrate the need for significant investment in “new” water supplies.

The report acknowledges that;

Casitas water demand in the past five years has been considerably lower than 17,500 AFY, reflecting the willingness of Casitas customers to modify water use practices in response to the drought.

But for the purpose of analyzing future scenarios;

Casitas staff felt it was reasonable to assume a permanent savings of 10% from the 2016 UWMP forecast. Thus, the effective Casitas UWMP demand estimate used in the CWRP analysis was 15,750 AFY.

It is important to note that current water use is estimated at 7,381 AFY (CMWD website, Aug 2020.) This is more than 3,000 AFY (30%) below the Safe Demand of 10,700 AFY, or a full 60% reduction from the 2016 UWMP projected demand.

The CWRP presents a Risk Analysis based upon a seemingly arbitrary demand of 13,000 AFY, with the assumption that no emergency measures would be taken. This is approximately 2,500 AF greater than Safe Demand. Not surprisingly, this analysis resulted in a long-term supply deficit, for which;

Modeling showed a supplemental supply of 2,500 AFY would adequately mitigate that risk if achieved within one to five years.

The report goes on to recommend a suite of projects totaling over $150M to secure the “missing” 2,500 AFY. The majority of this money is required for large infrastructure proposals to connect to the State Water Project. (Note that 2,500 AFY is less than half of annual evaporation losses from Lake Casitas.)

The table below provides a summary of the various Supply and Demand estimates:



Community Resilience:

Throughout the Ventura River watershed, the community has exceeded recommended reductions in water allocations. This includes customers of the other water districts who all share in the limited local supply. This dramatic reduction in water use is largely in response to the recent catastrophes, including the Thomas Fire and severe drought. The community has clearly demonstrated the ability for adaptation in a time of need. And as the CWRP recognizes, some of these changes have resulted in a permanent demand reduction through lawn replacement and other water saving measures.

CMWD recognizes the importance of working with the community it serves:

“The main mechanism to respond to water supply conditions is to rely on informed customers working in partnership with Casitas to limit water use to no more than the assigned water allocation and support the water use limitations with appropriate conservation penalties for water use in excess of the assigned, or adjusted, allocation.” - WEAP 2019

Yet at the same time, CMDW appears hesitant to fully develop this community partnership:

Customers have a limit to their tolerance for being asked to conserve. Casitas will need to gauge public perception on this topic when the WEAP is updated.” - CRWP 2020

In the meantime, the community has successfully accomplished the sustainable “Safe Demand” as determined by the updated Lake Casitas Yield Model by incorporating WEAP demand reductions in response to lake levels.



Demand Management:

Demand management is always more cost effective than infrastructure dependent new supply projects. And the Ventura River community is just getting started. Numerous local projects were identified in the Ventura River Watershed Plan, and several initiatives are currently underway to plan and implement decentralized solutions aimed at improving conditions in the watershed. Indeed, the watershed plan (which CMWD participated in) developed the consensus objective of maintaining independence from imported water based upon the numerous emerging initiatives identified in the report.

Sufficient local water supplies to allow continued independence from imported water and reliably support ecosystem and human (including urban and agricultural) needs in the watershed now and in the future, through wise water management. “ – Ventura River Watershed Management Plan 2015

However, the CWRP relegates Demand Management to the status of “conditional strategy,” only pursuing such local options if plans for the State Water Project connection do not come to fruition.

Additional Demand Management: Because the CWRP planning policies already include a 10% demand reduction compared to the most recent UWMP, the long-term supply gap was addressed through developing new water supply projects and additional demand management was recommended as a conditional strategy. It is recommended that Casitas develop a Water Conservation Plan to evaluate the potential savings and cost effectiveness of various conservation measures.



Cost Benefit Analysis:

As recommended in the CRWP, the potential savings and cost effectiveness of various conservation measures needs to be carefully examined and compared with the more expensive infrastructure projects. The community deserves a fair and unbiased accounting because it is they who will bear the cost of these decisions.

In 2011, a group from the Bren School of Environmental Science and Management at UCSB developed a watershed model and investigated the cost effectiveness of a suite of infrastructure and consumer- based projects. Aside from the effectiveness of “consumer-based” programs such as re-landscaping and greywater, their report, Sustainable Water Use in the Ventura River Watershed, determined that:

Raising water rates to reflect the true value of water within the Ventura River Watershed will help to avert even higher rate hikes in the future, which will occur if water purveyors are forced to purchase costly State Water to meet consumer demand. – Bren Study 2011

The Bren report concludes with;

Our final recommendations to watershed planners in the Ventura River Watershed are: 

(1) implement programs encouraging the increased installation of ocean friendly gardens and greywater systems in single-family homes,

(2) construct decentralized infiltration basins throughout the watershed, and

(3) increase CMWD and Meiners Oaks water rates to the state average.

Implementation of these strategies, coupled with responsible groundwater pumping, has the potential to increase water availability for human needs, improve ecosystem health, and improve water quality even in the face of climate change, land use change, and population growth.


Bren school project: Sustainable Water for the Ventura River Watershed

Alternatives developed:

Infrastructure Based Water Management Strategies

page4image339296000

Infiltration Basins

Pervious Streets

Scalping Plant

San Antonio Spreading Grounds

Consumer Based Water Management Strategies

Ocean Friendly Gardens

Greywater

Rate Increases to State Average

CMWD 33% Rate Increase



Pitfalls of the State Water Project:

Contrary to the advertised benefits, connecting to State Water potentially threatens to undermine the sustainability of the community that relies upon the Ventura River watershed. Full disclosure of the pitfalls of this strategy is required before the community becomes committed to higher rates for “paper water” that we may never receive.


Research continues to indicate that rising temperatures will result in changes in precipitation patterns, a significant decline in the Sierra snowpack, and early snow melt such that For the vast majority of potential future climate conditions, the State Water Project will have substantially more system shortages than what we’ve seen historically,” according to Dr. Geeta Persad, a senior climate scientist with the Climate and Energy Program at the Union of Concerned Scientists.

The California Water Impact network (C-WIN), a Santa Barbara based organization, published a 2017 report that demonstrates the cost impacts and consequences for State Water Project (SWP) participation to date, utilizing the experience of Santa Barbara County Coastal Aqueduct Project as an example of the statewide problem that will be encountered if the Twin Tunnels comes to fruition. The 'Santa Barbara Report' exposes the underlying problem of "paper water;" C-WIN spent three years gathering ... information through Public Records Act requests and Freedom of Information Act requests and found that consumptive water rights claims are at least 5 1⁄2 times more than available supply.

In a legal challenge against the City of Ventura’s State Water Interconnect Project, C-WIN states that:

The Interconnection Project is a major step backward from the growing recognition that local dependence on state water is a problem, not a solution, for water reliability and the environment. ...State water is so oversubscribed that the courts have identified more than half of its allocation as unreliable “paper water”.

The cost of state water will cripple Ventura’s ability to explore and develop sustainable regional solutions. ...Once a district is dependent upon the state water system, they’re responsible for the costs of the maintenance and new infrastructure of the entire SWP conveyance system. Ratepayers have no direct input and no ability to opt out of these maintenance and infrastructural decisions. The stated Ventura pipeline project estimate of $50 million does not include the exorbitant additional costs and risks of state water.

The EIR for the Interconnection Project evaded assessing the major impacts of growth encouraged by the false perception of state water availability. When the SWP predictably fails to ensure reliable deliveries, demands on other depleted sources such as groundwater, the Ventura River and Lake Casitas will only increase when it is too late to plan for integrated improvements in local water resilience.

These and other concerns voiced by the community regarding the long-term cost vs actual benefits indicate that State Water should be relegated to a “Conditional Strategy,” only coming into play if the local watershed-based strategy is not effective.


Conclusion and Recommendations:

The Draft CWRP provides an updated look at water supply and demand within the Casitas Municipal Water District service area. The new Safe Demand Policy provides a realistic assessment of the effectiveness of the WEAP action plan and community response to drought. This new perspective sheds light on the fact that the District is already achieving the newly prescribed Safe Demand which gives a 95% assurance that Lake Casitas will not drop below 20,000 AF of storage.

However, the report does not adequately acknowledge the need for greater coordination amongst the many agencies and individuals within the Ventura River Watershed. Groundwater provides a large proportion of the local water supply with Lake Casitas as backup, so integrated watershed management should be a priority. The community has shown a remarkable resiliency following the recent drought and fires, and the capacity for increased local water use efficiency should not be underestimated.

Based on the information provided in the Draft CWRP, CMWD has an opportunity to plan for local sustainability rather than develop the costly infrastructure for imported water. As recommended in the report, a full cost/benefit ($/AFY) analysis on a full range of alternatives should be conducted and management options should be prioritized by cost efficiency. The next step should be to develop a comprehensive water use efficiency and conservation policy and program to include:

  1. Integrated water budget for the entire Ventura River Watershed

  2. Coordination with partner agencies and the community

  3. Updated WEAP water allocations to comply with Sustainable Demand

  4. Increased water rates to a level that supports Sustainable Demand

  5. Support for watershed management programs to implement water efficiency and reuse, conservation, and groundwater infiltration and sustainable management


Casitas Water Reports: https://www.casitaswater.org/your-water/casitas-water-security


References:

Ventura River Watershed Management Plan, Walter, Ventura River Watershed Council, March 5, 2015. 

Sustainable Water Use in The Ventura River Watershed, Gardner et al, Bren School of Environmental Science and Management, University of California Santa Barbara, 2013

Climate change and the future of California’s water, Summary of presentation by Dr. Geeta Persad , Mavens Notebook, Nov 7, 2019

The Unaffordable and Destructive Twin Tunnels: Why the Santa Barbara Experience Matters, The California Water Impact Network, November 2017


On this Blog:

Casitas Water


Thursday, August 13, 2020

Retrospective on the Thomas Fire

The Ventura River has demonstrated amazing resiliency following the Thomas Fire.  The river appears healthier now than it has been in decades following the influx of sediment eroded from the mountains.  However, the initial flushes following the fire negatively impacted the river until the storms of 2019 "rolled" the bottom breaking up an impervious layer formed by ash and silt deposits.  The photos here are provided to illustrate what this looked like in the summer of 2018.

Ventura River, May 2020



Ventura River following the Thomas Fire, January 2018

 
Ventura River following the Thomas Fire, March 2018

The first storm immediately following the fire in January 2018 moved large amounts of black ash and very fine organic matter off the burnt hillsides. The second storm in March eroded additional fine sediments with a brown soil color.  These two events combined to form a hard crust on the stream bed.

The photos below from June 1, 2018 describe observations of this phenomenon. 


Ventura River 6-1-2018

The river bottom was embedded with ash and fine sediment that filled the voids and effectively "cemented" the cobble and gravel.  In the image above, a cobble was removed by hand to expose the layers below.  With no tools handy, it took considerable effort to loosen and remove this rock.

Ventura River 6-1-2018

Once a rock was removed, the hard crust could be broken up and pulled away by hand, further exposing the riverbed.  Here the substrate was agitated to allow the river flow to transport the fine sediments away.  The dark color of this plume indicates the organic ash eroded from the hillsides in the initial rain event.


Ventura River 6-1-2018


Removing a couple more rocks and agitating the surface eventually cleared this small area of river bottom.  The brown crust can be seen adhered to the rocks.  The image below provides an overview of the site.


Ventura River 6-1-2018



The upper Ventura River groundwater basin relies on flows infiltrating through the alluvium in the river reach downstream of the Robles Diversion.  The graphs below are from the monthly water update provided to customers of the Ventura River Water District.  This water district relies on wells in the Ventura River in the general vicinity of the photos above.  As noted at the time, groundwater levels did not  recover as normally expected in 2018.  However, the 2019 storms resulted in river flows that adequately cleaned out the river channel to allow recovered infiltration as illustrated by the 44 foot rise in groundwater in the bottom chart.  


Ventura River Water District, July 2018




Ventura River Water District, June 2019



On this blog:

March Rains - fires, flood, drought, and sand