Tuesday, December 15, 2015

River Parkway kiosk

December 14, 2015

The Ventura Hillside Conservancy in partnership with the Friends of the Ventura River installed an interpretive sign near the Main Street Bridge to promote the Ventura River Parkway.

The Ventura River Parkway is a long-term solution to ongoing threats to water quality and habitat in our local watershed.  The growing network of trails and parks will reconnect the community with the river and transform it into an asset for all to enjoy.

The sign includes 3 panels, shown below:

This project was made possible with funding from the Earth Island Institute and Tracey Warriner with support from the Southern California Wetlands Recovery Project, California Coastal Conservancy, the Wildlife Conservation Board.  Friends of the Ventura River sponsored the design and photography with support from Patagonia.

Surfers Point - first real test

Surfers Point Managed Retreat
Protective dunes
December 11, 2015

December 11, 2015 marked the first real test of the Surfers Point Managed Shoreline Retreat project.  Things have been relatively calm since the project was constructed in 2011.  But last week, the first sign of this year's much-publicized "El Nino" materialized, coinciding perfectly with the new moon and morning high tide.  The swell registered 25ft at 17 seconds from 295 degrees on Harvest buoy. Although the predicted tide was 6.2 ft above "mean sea level," sea level has been recorded up to 1 foot higher this year due to warm surface waters throughout the Pacific Ocean.  A tsunami gage recently installed at the Ventura Harbor recorded sea levels over 8.2 feet!  Storm surge combined with
phenomena termed "wave setup" and "wave runup," produced large surges of water causing unprecedented coastal flooding in Ventura.

Coastal Flooding, Hanover Lane, Pierpont Beach
Ventura CA   Dec 11, 2015

The Surfers Point Managed Shoreline Retreat project combines restoring adequate setback with an engineered cobble berm and vegetated dunes to enhance coastal resiliency.  This first test proves this concept quite dramatically.  (It is ironic that the dunes at Surfers Point were constructed with sand from dunes that were removed from Pierpont beach due to beachfront homeowners objections to losing their views and recreational space!)

The photo below shows that although the seaward edge of the dunes was eroded, overtopping was kept to a minimum.  The loss of the seaward edge of these dunes was expected, and they will grow back  during the summer months.  This illustrates the value of "retreat."  Allowing space for the beach, dunes, and cobble to come and go naturally is a welcome change from the crumbling asphalt and concrete that were removed from this site.

Surfers Point Managed Retreat
Foredune erosion and overtopping
December 11, 2015

The photos below are shown to illustrate the difference between the Managed Retreat project area and the parking lot that remains until Phase 2 is funded.  Although there was no damage to the bike path and parking lot this time, the entire area got wet with overtopping waves.

Surfers Point Managed Retreat
 overtopping downcoast of retreat zone
December 11, 2015
Surfers Point Managed Retreat
overtopping at phase 1 boundary
December 11, 2015

The following sequence illustrates the function of the buried cobble berm.  The summer waves bring  sand back to the beach every year, completely burying the exposed edge of the cobble berm.  Winter swells remove this sand and expose the cobble beneath.  The cobble naturally forms a berm which is very effective at absorbing wave energy.  Note that this site is on the Ventura River Delta where cobble is a feature of the natural beach.  Also note that the hard escarpment is a result of "sand" that was imported from an inland source during construction.  Despite engineering specifications that limited the percentage of fine sediment in this material, there was enough fine silt and clay to firmly cement this layer.  Erosion events like this will remove this fine material over time leaving a more natural sand and cobble beach.

Surfers Point Managed Retreat
Summer beach profile
Sept 18, 2015

Surfers Point Managed Retreat
Winter beach profile
December 2, 2015

Surfers Point Managed Retreat
Extreme event response
December 11, 2015

These next two photos show how much sand was removed during the large swell of December 11. Also compare the degree of overtopping during the high tide of December 2nd vs that of December 11.  (Remember that this cobble berm will once again be buried in sand next summer.)  The rocks in the right foreground are the "spur groin" on the end of the Ventura River levee.  This structure focuses wave energy onto the cobble berm, which was the cause of greatest erosion prior to construction of the managed retreat project.

Surfers Point Managed Retreat
Cobble berm from the west
December 2, 2015

Surfers Point Managed Retreat
Cobble berm from the west
December 11, 2015

It is also interesting to compare those areas with established dunes versus a flat beach.  Although the dunes were slightly overtopped or wetted in the low spots, large surges of seawater completely flooded the recreation area used by kite boarders.  (Note that this flat area was not part of the original plan, but was modified during construction.  While this actually enhances this "living laboratory" opportunity, it is clearly the weak link in the project.)  Also note the blown sand in the foreground of the second image:  this is the only location where sand is not captured by vegetation, often resulting in sand blown onto the bike path.

Surfers Point Managed Retreat
Dunes vs flat beach
December 11, 2015

Surfers Point Managed Retreat
Dunes vs flat beach
December 11, 2015

The Surfers Point Managed Shoreline Retreat project performed as designed during the first significant swell since construction.  We shall continue to maintain and monitor the site to demonstrate the advantages to this approach to coastal management compared to the hard structures of traditional coastal engineering.

Special thanks to all the partner agencies who made this project possible!

More on this blog:  Surfers Point

More project history:  SurfersPoint.org


C-St Ventura - cobble and erosion Dec 2015

In February 2014, the City of Ventura constructed a cobble berm to protect the public amenities along the promenade and bike path in Ventura.  Surfrider documented this project, and noted the rapid migration of the imported river rocks along the shoreline.

On December 11, 2015, a large westerly swell flooded the Pierpont neighborhood and damaged the Ventura pier.

Ventura pier, Dec 11, 2015

  Not surprisingly, one of the palm tree planters along the promenade at C-St collapsed into the surf.

C-St palm tree planter collapsed from coastal erosion during swell event of Dec 11, 2015

Surfrider had contacted the City in October when it was evident that the planter was at risk.  Apparently others had expressed the same concern.

C-St palm tree planter at risk of erosion Oct 26, 2015

As a result of public concern for the palm trees, Ventura City Council approved "emergency funding" to renourish the cobble berm.  Unfortunately the funding approval came too late, and re-nourishment is not expected until after the new year.

Here's the cobble berm with sand "cap" shortly after it was constructed in 2014:

This is what it looked like on Dec 11, 2015:

C-St cobble berm - palm tree planter failure - Dec 11,  2015

Looking west from the Figueroa storm drain
C-St cobble berm Dec 2015
Looking East from Figueroa storm drain
C-st cobble berm Dec 2015

C-St cobble berm - promenade stairs - Dec 11,  2015

Promenade stairs - Dec 11,  2015

It is evident from our monitoring and these images that much of the cobble migrated down into the cove.  A significant berm formed during recent winter swells in front of the promenade stairs.  This berm provided protection for the stairs that have suffered damage in past winters.

So although the cobble nourishment did not protect the palm trees during this largest swell in recent history, it did provide a benefit to the promenade just downcoast.

The city has a Coastal Commission permit for ongoing nourishment along Surfers Point.  Although the one-time nourishment done in 2014 did not provide the anticipated level of protection, regular nourishment would progressively add volumes of cobble for more protection.

Although it is tempting to call for a more permanent revetment to protect the palm trees along the promenade, this would have other impacts.  Coastal structures exacerbate erosion downcoast.  They also disrupt coastal processes and recreational access to the beach.


Ensure Ongoing Funding:
Surfrider recommends that the City of Ventura establish a permanent budget for beach maintenance with oversight by a qualified coastal engineer.  Regular monitoring and renourishment is necessary to maintain a beach to protect the promenade in its current location.

Simplify Implementation:
We also recommend that the strict engineering specifications for constructing a cobble berm be waived in favor of a less expensive and more frequent nourishment.  It was clear during construction  that the waves quickly re-worked the carefully graded cobble berm, undoing thousands of dollars of work in a matter of hours.   A more efficient use of funds may be to simply dump smaller quantities of cobble in an easily accessible location and allow the ocean to work it into a berm.

Complete the Planned Managed Retreat:
It may also be beneficial to consider implementing Phase 2 of the Surfers Point Managed Shoreline Retreat project as envisioned.  The additional large quantity of sand and cobble would ultimately benefit the downcoast beach.  However, this would not eliminate the root cause of the problem.

Solve the Root Cause of Erosion:
The root cause of the erosion problem is infrastructure built too close to a shoreline that is receding due to rising sea levels and a sediment deficit. There's not much that can be done locally to combat rising seas, but it is noteworthy that record tides up to one foot above the predicted high tide have been recorded this year due to the warm water in the Pacific Ocean.

The current sediment deficit is the result of the long-term drought.  Indeed, the erosion which damaged the then-recently constructed bike path in 1991-1992 occurred during the last major drought.  This year's much-anticipated el nino floods, if equivalent to the big events in the past, will deliver a large quantity of sand and cobble to the river mouth. This sediment will naturally fill in along the point providing a benefit for many years.

Of course, the ultimate long-term solution is the restoration of the Ventura River through the removal of Matilija Dam.  This project is necessary for many reasons, but it was beach erosion that kicked off the first studies in 1998.  Much progress has been made on that project, but funding remains a major hurdle.

More info on this blog:

Ventura River Ecosystem: C-Street, Ventura - more cobble berms
The Managed Retreat Process at Surfers Point
Surfers Point Working Group considers phasing plan
Surfers Point Managed Shoreline Retreat
Matilija Dam

In the News:

The perfect storm - VCReporter
High tide, high surf cause debate, erosion on Ventura beaches
By Michael Sullivan 12/17/2015

Ventura beach disappointment 
VCReporter    Letters 12/31/2015
It is unfortunate that the city of Ventura has opted for a “hard solution” to coastal erosion at Surfers Point following the loss of a palm tree along the promenade. Indeed it’s ironic since the city was a strong proponent of the highly successful “managed shoreline retreat” project on the adjacent section of the point managed by the Fairgrounds. It’s also disappointing considering that they have a standing permit to renourish the beach with sand and cobble, but have been unable or unwilling to dedicate funding to maintain Ventura’s greatest asset. Indeed, intentional neglect is a useful strategy used to invoke the “emergency” loophole in the California Coastal Act.
Beachgoers will soon have to negotiate “a 265-linear-foot rock revetment, approximately 15 feet tall and 30 feet wide, consisting of approximately 1-3-ton stones.”  And it will not be long before the erosion caused by this new structure will necessitate even more rocks, forever changing Ventura’s famed “C Street” surf break.
Paul Jenkin
Surfrider Foundation, Ventura Chapter

UPDATE Jan 31,2016

Following much discussion, the City of Ventura has decided to exercise their right to the Emergency Permit issued by the California Coastal Commission.  
Surfrider expressed concerns that a rock revetment will exacerbate downcoast erosion, perhaps leading to additional armoring in the future as well impacting the recreational beach.  We also suggested that the event of December 11 was an extreme event, even in this round of El Nino storms and swells, and the loss of a palm tree did not constitute an immediate threat to the promenade.
The revetment will be considered "temporary" until a Coastal Development Permit is issued by the commission. The City has indicated they will reevaluate the situation following the winter season and seek funding to assess their alternatives.
Surfrider shall monitor the effects of this structure and retain the right to appeal the final permit. 

Monday, December 14, 2015

1969 Floods and Ventura wastewater

As we prepare for 2016's predicted floods, it is interesting to look back in history.   The photos below illustrate the impact to the City of Ventura's wastewater infrastructure from the big floods of 1969.  The Santa Clara River jumped its banks and flowed around the wastewater treatment plant into the Ventura marina.  Broken pipes spilled raw sewage into the ocean for weeks.  

In many ways the wastewater treatment plant located at the mouth of the Santa Clara River continues to become increasingly vulnerable over time.  Upstream development has led to new and bigger levees, effectively channelizing the river and increasing flows near the river mouth.  Moreover, as time goes by climate change will compound the problem through increased storm intensity which will add to the threat of flood from upstream, while rising sea levels present a growing risk from the ocean.

The Olivas Park golf course was historically a productive wetland, which also provided an effective buffer to flood waters along the banks of the Santa Clara River. As illustrated below, in 1969 the river flowed right through the recently constructed golf course and into the marina.   

Solutions:  Surfrider has commented on the Santa Clara Estuary Special Studies that Ventura Water should take advantage of ongoing plans to reduce discharges into the Santa Clara Estuary through wastewater recycling, and consider developing a decentralized strategy.  This would over time reduce the volume of wastewater reaching the estuary, and increase resilience in the face of these risks.

More info:

Santa Clara River Estuary Special Studies
Ventura River Watershed - Flooding photos

Monday, December 7, 2015

Meiners Oaks stormwater project

In fall 2015, the Ventura County Watershed Protection District completed construction of an engineered bioswale to capture low flow runoff from El Roblar Rd in Meiners Oaks.  This County project was funded through a Prop 84 Stormwater Grant in partnership with the Ojai Valley Land Conservancy and is located within Land Conservancy's Meadow Preserve.  The Surfrider Foundation and other organizations contributed letters of support for the project.

The completed project is shown here post-construction (photo taken Nov'15.) Note the seeding, planting, and irrigation.  Vegetation should fill in with the upcoming winter rains.

The swale is designed as treatment diversion, taking runoff from the street, filtering it, and returning any overflow to the existing storm drain. The engineering features of this project are shown below.  Flow enters at the upstream/right side through a storm drain inlet at the curb.  Water is filtered in the trash/nutrient/sediment removal baffle box before entering the vegetated swale.  Water that is not absorbed into the ground as it flows through the swale will exit back into the storm drain.  

The project will capture and treat runoff from about 40% (36.8 acres) of the Meiners Oaks urban area as shown below:

The image below shows the drains within the larger Meiners Oaks area - these storm drains all enter the Ventura River where Happy Valley Drain exits the bluff along Rice Rd (bottom left of the image labeled MO-MEI).  The original proposal included two other projects on McDonald Drain which illustrate components of a regional watershed approach to capturing urban runoff.  These components were not funded.

The County will be monitoring this project over the coming rainy season to evaluate the effectiveness of the engineered bioswale.  Once the vegetation is established they will be measuring flows and collecting influent and effluent samples for BMP effectiveness evaluation to reduce nutrients and other stormwater pollutants.

For more information:

Ewelina Mutkowska
County Stormwater Manager (805) 645-1382 Ewelina.Mutkowska@ventura.org

Salvador Diaz-Rubin, PE
Design Engineer
(805) 650-4066 Salvador.DiazRubin@ventura.org