Monday, February 12, 2018

County Approves Matilija Dam Contract


Feb 6, 2018 - The Ventura County Board of Supervisors approved a contract for technical studies on Matilija Dam removal.  This is the first phase of the work plan funded through a $3.3 million California Department of Fish and Wildlife Proposition 1 grant received by the county in May, 2017.

This dam removal feasibility study will include:

  • Field Investigations of Reservoir Fine Sediment and Evaluation of Dam Concrete
  • Structural Evaluation of Orifice Alternative
  • Sediment Transport Modeling
  • Hydraulic Studies Based on Sediment Modeling 
  • Re-evaluation of Downstream Project Components 
  • Assessment of Flushing Storm Events
  • Dam Removal Concept – 10% Level Design
  • Updated Structural Analysis of Dam


The $822,302 contract with engineering firm AECOM is Phase 1 of the $3.3 million Matilija Dam Removal 65% Planning Design Project.

Field work is to commence 7/7/2018 with The Final Dam Removal Feasibility Report to be completed by 07/11/2019.

In the news:

Ojai Valley News Feb 8, 2018




More on this blog:     Matilija Dam



...

Wednesday, January 31, 2018

Matilija Dam - water quality

Matilija Dam,  decaying debris, Jan 26, 2018 

Ventura River preserve, Jan 30, 2018
Two weeks after the flood, floating debris remains trapped near the dam.  There was a significant input of organic matter that has stagnated in the reservoir, as evidenced by the smell.  Flows entering the reservoir from upstream in Matilija creek as well as in the North Fork Matilija Creek are much cleaner.   This is having a tremendous impact on downstream water quality all the way to the ocean.





This is consistent with known reservoir impacts in general, and our experience monitoring Matilija Dam over the years.  Under normal circumstances Matilija reservoir often retains suspended particles for weeks following a storm, greatly extending the negative effects of turbidity downstream.  In the current situation, whatever has accumulated behind the dam has magnified this problem.










Matilija dam and reservoir, Google satellite image, after fire and flood, Jan 13, 2018







Rodents seemed most susceptible to wildfire
It is likely that any wildlife killed by the fire along with materials from destroyed residences has washed into the reservoir along with the vegetation that was stripped from the floodplain.  Extremely high turbidity killed fish in the reservoir.  The recent warm weather and stagnant water has created a toxic brew, which is slowly being released downstream.







Although there have been concerns raised over the years regarding the negative effects of releasing reservoir sediment, this illustrates how removal of the dam will in fact enhance water quality once the initial flush is complete.



Deer carcass, found elsewhere in the
watershed following Thomas Fire






















Dead bass, found downstream in the Ventura River Preserve




Upstream of dam, Jan 26, 2018
Downstream of the dam, gauging station, Jan 26, 2018


Ventura River Preserve  Feb 12, 2018


On February 3, 2018, Santa Barbara Channelkeeper's Stream Team volunteers collected water samples throughout the watershed.  In particular, the results demonstrated a significant impact from the dam, with bacteria and nutrient levels spiking below the dam and slowly decreasing downstream. Note that these levels were orders of magnitude above those that have been recorded since 2001!




In the news:  ojaivalleynews.com



Tuesday, January 30, 2018

Matilija Canyon, before and after the flood


This photo set illustrates the change in the Matilija Canyon floodplain from fire and flood,  following the Thomas Fire.

Matilija Canyon, looking upstream near Ecotopia, Dec 26, 2017

Matilija Canyon, looking upstream near Ecotopia, Jan 26, 2018

Matilija Canyon, looking downstream near Ecotopia, Dec 26, 2017

Matilija Canyon, looking downstream near Ecotopia, Jan 26, 2018

Google aerial - before

Google aerial - Jan 13, 2018
Aerial overviews from Google Earth Crisis map


Tuesday, January 16, 2018

Letter: Santa Clara River Estuary


January 16, 2018

Gina Dorrington
Ventura Water
501 Poli Street, Room 120 Ventura, CA 93002

via email: gdorrington@venturawater.net

RE: SCRE Special Studies – Water Recycling Opportunity

Dear Ms. Dorrington:

The Ventura County Chapter of the Surfrider Foundation has voiced concerns with water quality at the mouth of the Santa Clara River since our Blue Water Task Force identified high bacteria levels at this popular surfing location in the early 1990’s. Recognizing the benefits of integrated water management, the Surfrider Foundation has been a longtime proponent of recycled wastewater to enhance our coastal ecosystems. Wastewater discharges have historically impaired coastal water quality, and even with advances in technology, increased nutrient levels impact receiving waters.

We would like to re-state our support for 100% recycling of the city’s wastewater to eliminate the discharge into the Santa Clara River Estuary.

We do not concur with the analysis presented at the November stakeholder meeting that oversimplify the ecosystem associated with the Santa Clara River Estuary (SCRE.) Indeed, as other commenters have noted, this system is in fact much more representative of a coastal lagoon, since it does not maintain a perennial opening to the ocean. Indeed, it is this fact that creates the problems with the wastewater discharge. Without a regular exchange between the lagoon and the ocean, nutrient rich wastewater accumulates in an unnatural manner behind the beach berm. Only during large winter storm events or human intervention does this lagoon breach. This results in unnaturally high water levels and poor water quality.

Finding of Enhancement is Flawed:

Any conclusion that determines that the lagoon is enhanced by the wastewater discharge are flawed. Although the resource agencies rightly are concerned for the endangered and special status species that rely on habitat at the mouth of the Santa Clara River, current conditions limit, rather than support those species. The unnaturally high water levels resulting from the discharge create a simplified pond habitat that is subject to episodic draining. Sea water exchange, a necessary part of this ecosystem, is also precluded with the flooded lagoon. The elimination of habitat complexity and poor water quality has created an ideal habitat for non-native species, most prominently carp. From our experience on the Ventura River, carp are the predominant fresh water species below the Ojai Sanitary District discharge on the lower Ventura River, relegating this reach to migratory status for the endangered Southern Steelhead. Steelhead may survive in such an environment, but they certainly wouldn’t choose it.

An Opportunity for Ecosystem Benefits:

A more complete ecosystem view of the situation has not been conducted as part of the SCRE analysis. By focusing exhaustively and exclusively on the Santa Clara River Estuary, the potential benefits of eliminating the wastewater discharge have not been fully considered. Consider this fact:


50% or more of the discharge originates from the Ventura River


The City of Ventura relies on a wellfield at Foster Park and surface storage from Lake Casitas for more than half the water supply. Both of these sources are currently stressed from over allocation during the prolonged drought.





How could a point source discharge directly into the Santa Clara River Estuary be considered to mimic “natural” processes and enhance the habitat, when much of the water originates from the adjacent watershed?

Most significantly, studies have documented the high quality spawning, rearing, and refugia habitat in the Ventura River upstream of the Foster Park wellfield. However, flows in this reach have become seriously impaired by over-extraction of groundwater, to the point that in recent years this refugia habitat has dried up for extended periods during the critical summer and fall months. It should be noted that this reach of the Ventura River was historically known as the “live reach,” for the rising groundwater in the vicinity of Casitas Springs, which was also named for this phenomenon. These are precisely the conditions that favor native species such as the southern steelhead. Indeed, recent population surveys have documented the presence of native trout in this reach.

Water Budget Perspective:

Consider the potential benefits from developing a “new” supply from recycled water. These slightly outdated supply and demand numbers are taken from the City's 2013 Final Comprehensive Water Resources Report. It is evident from this graph that if 'new' sources of water are not found the city will outgrow its water supply in the near future.




The red arrow shows that the potential for recycled water in Ventura is close to 50% of demand. (Of course the actual volume would be less than this depending on treatment and reuse options, but this demonstrates the overall magnitude.) Therefore water recycling would provide an opportunity to eliminate the flooding problem at McGrath as well as offset municipal water demand (i.e. an 'integrated solution'.) This demand offset could provide an opportunity to reduce pumping at the Foster Park wellfield during dry months of the year to sustain the critical habitat within the “live reach” of the Ventura River.



Recommendation:

We encourage the City of Ventura and the stakeholder resource agencies to carefully reconsider the potential benefit from maximizing the recycled water potential. Rather than choosing to maintain an artificial pool at the Santa Clara River Estuary, which has very limited habitat benefits, demand offsets gained through recycling 100% of the wastewater effluent may be applied to the enhancement of the comparatively high quality habitat in the Ventura River. In turn, the coastal lagoon will return to a more natural hydrology with improved water quality and habitat, while also eliminating the non-native habitat conditions that are currently degrading the SCRE ecosystem.

Sincerely,

A. Paul Jenkin, M.S.
Ventura Campaign Coordinator, Surfrider Foundation (805) 205-4953
pjenkin@surfrider.org

cc: SCRE Stakeholder e-mail list 

References:
Steelhead Population and Habitat Assessment in the Ventura River / Matilija Creek Basin 2006-2012 FINAL REPORT

Ventura River Ecosystem - wastewater, VenturaRiver.org 

Wednesday, January 10, 2018

Post fire storm event, Jan 9 2018


Flows over Matilija Dam following Thomas Fire, Jan 9, 2018, 8 am


January 9, 2018 Storm totals 
On January 9, 2018, the watershed received a significant storm following the Thomas Fire.  The bulk of the rain fell overnight and early in the morning of January 9.  Fortunately the highest intensity rainfall  missed our area and did not result in the widespread destruction seen up the coast in Montecito.  Forecasters had predicted up to 9" in the mountains, whereas we actually received 5-6" with only 1-2" in the lower elevations.

While many of the county gages appeared to have been damaged, USGS was out surveying at Foster park during the storm (red stars on hydrograph.)  Peak flows at Foster Park were over 10,000 cfs, with perhaps 6,000 cfs originating from Matilija Canyon.  The hydrograph shows the effect of heavy rainfall around midday which bumped the flow back up.
The water during initial runoff was very black, as expected with all the ash from the fire.  The river remained very dirty into the evening hours.  


Ventura River looking downstream from Hwy 150 bridge, Jan 9 2018 at 3pm
Ventura River at Santa Ana bridge, Jan 9 2018 at 12pm


Ash and turbid flow, Ventura River Preserve Jan 9, 2018




The storm cleared rapidly in the afternoon, producing striking rainbows throughout the valley.

Clearing storm over the Ventura River at Hwy 150, Jan 9 2018, 3 pm


Suspended sediment from the erosion of the burn area persisted in the river for the next few days.  Fine sediment deposits along the riverbank can be seen in the photos below.

Confluence with San Antonio Creek, Jan 10, 2018


Casitas Springs Levee, Jan 10, 2018
Casitas Springs Levee, Jan 10, 2018


FosterPark, Jan 10, 2018


Foster Park bridge looking downstream, Jan 10, 2018

Foster Park bridge looking upstream, Jan 10, 2018

And of course, it all runs out to the ocean...

C-St webcam Jan 10, 2018



Friday, December 29, 2017

Thomas Fire



NASA Earth Observatory image by Joshua Stevens, using Landsat data from the U.S. Geological Survey
and ASTER GDEM data from NASA/GSFC/METI/ERSDAC/JAROS,
and U.S./Japan ASTER Science Team. 


The Thomas Fire burned throughout the month of December, destroying over 1,000 structures and becoming the largest wildfire in California history.  The immediate cost escalated over $300 million, plus an undetermined loss of property.  Almost 300,000 acres of open space has been transformed, including most of the Ventura River watershed.  Although the fire overwhelmed first responders on the night of December 4th, the subsequent mobilization and coordinated response of thousands of firefighters ultimately saved the populated areas of the Ojai Valley.


WIFIRE Firemap 12-28-2017



According to the Ventura River Watershed Plan (Part 2, p75):

• Wild fires can threaten local water quality and supply. Moderate wild fires occur once every 10 years on average, and extreme wild-  fires once every 20 years.
– Fifty-four percent of the watershed burned in the 1985 Wheeler Fire.
– Wild fires threaten water supplies largely by causing damaging sedimentation and siltation of reservoirs. Equipment damage, interrupted power supply, ash deposits, and use of water for  re suppression are other potential impacts.

The Thomas Fire will undoubtably have a major impact on the Ventura River watershed for the foreseeable future.  Increased sedimentation will lead to severe flood risk, and significantly reduce the capacity of Lake Casitas and ability to divert water from the Ventura River at the Robles Diversion.

Matilija Dam looking upstream following the Thomas Fire, Dec 26, 2017


Hydrology, Hydraulics, and Sediment Studies
 for the Meiners Oaks and Live Oak Levees
Detailed analyses of sediment transport have been conducted for the Matilija Dam Ecosystem Restoration Project.  It has been estimated that approximately one half of the 7 million cubic yards of sediment trapped in Matilija reservoir was delivered during the 1969 El Nino storms which followed a fire in Matilija canyon.  Studies estimate that the reservoir will be filled with sediment by 2030, at which point coarse sediment (sand, gravel, and cobble) will begin to pass downstream.  That process has now been accelerated.  Computer modeling identified deficiencies in the downstream infrastructure's ability to withstand an increase in sediment loading with dam removal.    The sediment regime has now been altered, and future modeling under the Prop 1 grant will need to account for these changes.

Meanwhile, it is likely that the next major flood will deliver sediment loads in excess of that expected with dam removal, placing downstream communities at risk.  For example, the image here illustrates how the Santa Ana bridge and Live Oak levee in Oak View create a choke point in the river which is likely to back up and overflow with high sediment loads in the river.


The Ventura River Watershed Council will discuss the impacts of the fire:

Thursday, January 4, 2018 / 9-11:30am
Oak View Park and Resource Center Auditorium
555 Mahoney Ave. Oak View, CA 93011

Agenda can be found here.


More info and how to help: https://ovlc.org/thomas-fire-updates/


In the News:

Ojai residents take stock of their blessings — and vulnerability — after surviving the Thomas fire, LA Times Jan 8, 2018

"If substantial rain comes down, I expect sediment and debris to flow over the spillway," said Peter Sheydayi, deputy director at Ventura County Watershed District. "We're in the midst of working on risk reduction measures such as installing debris flow sensors to determine whether evacuations are needed."
"The dam itself," he added, "is safe."
Paul Jenkin, an environmental activist in Ojai and founder of the Matilija Coalition, a nonprofit group dedicated to restoring the Ventura River, is not so sure. Surveying the structure from an overlook and shaking his head in dismay days before the rain, Jenkin said, "Obsolete dams like this one are ticking time bombs."
Officials say there are roughly 8 million cubic yards of debris behind the dam now. "So the next big storm will push huge amounts of mud and water over the top, overwhelming bridges, culverts and roads below," Jenkin said.





Thursday, November 30, 2017

Natural Shoreline Case Study


A report published in November 2017 features the Surfers' Point Managed Shoreline Retreat project as an example of Natural Shoreline Infrastructure for adapting to sea level rise.  The report states:

Sea level rise and erosion are major threats to California’s coast, requiring solutions to preserve the many benefits a healthy coastline provides:  flood protection, recreation, habitat for wildlife, water quality and more. Seawalls and other engineered structures, are commonly installed in order to hold the shoreline in place and hold back the ocean; however, they ultimately make the situation worse in most cases by increasing erosion and thus causing already vulnerable shorelines to shrink more.
Natural shoreline infrastructure is an alternative that is more likely to preserve the benefits of coastal ecosystems while also maintaining coastal access.  

Five projects that spanned the California coast and represented different coastal settings and corresponding approaches were selected for the purposes of this report. From South to North these include:

  • Seal Beach National Wildlife Refuge Thin-layer Salt Marsh Sediment Augmentation Pilot Project,
  • Surfers’ Point Managed Shoreline Retreat Project 
  • San Francisco Bay Living Shorelines:Nearshore Linkages Project
  • Hamilton Wetland Restoration Project
  • Humboldt Coastal Dune Vulnerability and Adaptation Climate Ready Project

These case studies were designed to be useful examples for coastal planners, local governments, and others working on solutions and making decisions regarding climate-related coastal hazards.

Of these, Surfers' Point and Humboldt Dunes are the only projects implemented on the active coast, while the others are in bays and estuaries which are not directly affected by erosion by ocean waves.  And Surfers' Point remains the sole example of managed retreat in response to coastal erosion on a developed shoreline.

One key lesson from the Surfers' Point case study is: 

  • Restoration of the backshore is a more effective approach to re-establishing shore morphology with desired ecology, restoration, and ecosystem services than the more traditional approach of building the shore seaward.
The full report my be downloaded here: 

More information:


Reference:  Judge, J., Newkirk, S., Leo, K., Heady, W., Hayden, M., Veloz, S., Cheng, T., Battalio, B., Ursell, T., and Small, M. 2017. Case Studies of Natural Shoreline Infrastructure in Coastal California: A Component of Identi cation of Natural Infrastructure Options for Adapting to Sea Level Rise (California’s Fourth Climate Change Assessment). The Nature Conservancy, Arlington, VA. 38 pp