Where Should the Sediment Go? The Devil's Gate Dam Dilemma

UPDATE 8/2/2011: The Pasadena City Council unanimously approves use of Johnson Field for sediment storage during LA County's interim project to remove sediment buildup behind Devil's Gate Dam.

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To understand the current dynamics playing out in the Hahamongna about sediment removal behind Devil's Gate Dam, we must look at what got us to this point.

Here's a short recap:

.The 2009 Station Fire wildfire burns almost 70% of the upper Arroyo Seco watershed, depositing over 1,000,000 cubic yards of sediment into the Hahamongna Basin, much of which collects behind Devil's Date Dam
.LA County plans to remove all sediment in the Basin under 'emergency' maintenance procedures which do not require an Environmental Impact Report
.The local environmental community protests and the LA County Board of Supervisors approves a resolution requiring a complete EIR be done before sediment removal occurs, with the exception that County Public Works can remove 25,000 cubic yards this summer directly behind the Dam because of emergency maintenance conditions.
.LA County Dept of Public Works finalizes its interim sediment measures and starts conducting community outreach meetings to review truck transportation routes to haul the sediment out of the Basin for relocation to Scholl Canyon.
.The interim sediment removal plan must be completed by October 15, 2011, when the annual rainy season traditionally begins.

Yet the controversy seems to go on....

Why?

First, while LA County has put together a generally sound interim sediment plan, it has failed in its ability to properly communicate this plan to the public. Case in point: last Thursday night's outreach meeting at La Canada High School to discuss the 'truck haul' plans. What didn't go wrong?  The powerpoint did not work. There were no handouts. A new alternative #4 to keep the sediment in the Basin was announced with little context as to why this option was now being offered. Presenters seemed to be at a loss to directly answer many questions posed by the attendees.

But the enviro community and residents are not blameless here, either. Numerous bloggers, local residents and environmental organizations continue to disseminate skewed information and promote 20th Century style scare tactics online and in whisper campaigns to rally their troops towards either stopping this sediment removal or warning of 'dire' consequences if it occurs. They aren't offering any proactive alternative solutions, either.

So let's look at the facts relevant to public safety. (All these documents are online and available to the public at the dpw.lacounty.gov site.)

If you click on the header to this blog, you will be taken to the  LA County Staff Report to the Board of Supervisors which accurately discusses the issues. Then take a look at the powerpoint for the interim removal plan here:

tp://dpw.lacounty.gov/wrd/removal/DevilGate/CVAC_Interim_Measures_20110525.pdf

When we cut to the chase these facts remain:

1. The sediment directly behind Devil's Gate Dam has reached a level of 1,009 feet
2. This sediment is blocking at least two sluice gates, which are responsible for releasing water through the flood gates.
3. This sediment is also close to clogging the outlet valves at the top of these sluice gates.
4. This sediment, if not removed this summer, will likely clog outlet valves, including tunnel water outlets after the next rainy season.

Clogged sluice gates and tunnel water outlets mean that the Watermaster will be unable to discharge water through the dam.

Here's the unknown: how much precipitation the Arroyo Seco watershed will get this rainy season. It's especially difficult to predict because we are now experiencing chaotic weather patterns, witnessed by Mississippi River flooding, deadly Southern tornados and a West Texas drought and fire storm. As one local example, the experts at NOAA predicted a 'dry' La Nina last year and we got instead one of the wettest seasons in recent years. Should we have another wet rainy season, even more sediment will flow into the Hahamongna, resting behind the Dam.

Based upon these facts, can we really afford to take the risk of doing nothing about sediment removal behind the Dam this summer?

Let's review the sediment removal 'haul out' options (see the map on the powerpoint link). Unfortunately, projects of this scope and type always have short-term negative impacts on the local community. Truck traffic with attendant noise over the 4 week haul out time period will inevitably be a short term nuisance to affected residents and local commuters (JPL, La Canada High students, park users).

It's totally understandable that residents are concerned about the County's initial preference to use Alternative Route #1 down Windsor Boulevard. For the County, it is the fastest route out and will require the minimal infrastructure work to get this job done. For years, these residents have dealt with the noise and congestion of heavy trucking on this roadway due to the La Vina development, the City of Pasadena's water treatment plant construction, and regular deliveries to JPL.

That's why the recent agreement between the County and the City of Pasadena Water and Power which makes the availability of Johnson Field, located on the northeast side within the Hahagmongna Basin, as a sediment removal holding site welcome news. Use of Johnson Field will decrease truck hauling by 80% since only 20% of the organic materials will have to be hauled out of the Basin itself. The remainder will be hauled to and 'stored' on Johnson Field, which has not been used as a playing field for years.

The local in-basin haul to Johnson Field will also support the short timeline the County has to move this buildup because sediment needs to be 'dried out' first before it can be relocated due of its heavy weight when saturated by water.

Ultimately, there is no solution that will make everyone 100% happy, so it's important to keep our focus on the big picture. The Hahamongna is first and foremost a flood control basin and water conservation reservoir. We continue to face dire long-term local water reliability challenges. Unfortunately, this past winter's extremely wet season has blunted our awareness that we still need to conserve water. All three of Southern California's imported water sources remain in distress. Beyond immediate public safety concerns, sediment buildup behind Devil's Gate Dam significantly reduces the amount of groundwater that can be stored for local recharge in the Hahamongna Basin.

All rivers carry both water and sediment. There is ample opportunity for all of us to work towards a fully integrated long-term strategy for sediment removal as part of the full sediment removal plan and EIR for the Hahamongna. In the meantime, let's support the interim sediment removal measures, including Johnson field Alternative #4 transport, so that our focus can be on proactive solutions for the future rather than on emergency disaster cleanup and a real risk to public safety.

Los Angeles River Cooperation Committee Chooses First Project

Monday January 10th marked the first meeting of the newly reorganized Los Angeles River Cooperation Committee, comprised of representatives from the City of Los Angeles Engineering Office/LA River Office, Bureau of Sanitation, Recreation & Parks Dept as well as the Watershed Management and Water Resources Divisions of the LA County Flood Control District. The US Army Corps of Engineers participates as a non-voting member.

Committee Co-Chair Gary Lee Moore, of the LA Engineering Office, presided over a full agenda and a packed house, including community representatives from Friends of the Los Angeles River, Northeast Trees, Silver Lake Conservancy, Native Plant Society, and the LA Fire Department Search and Rescue Division.

Two major topics dominated this meeting: First, regional representatives of the California High Speed Rail Authority (HSR) gave an informative update on HSR alignment crossing the Los Angeles River along three vital segments: Los Angeles Union Station to Palmdale (which also affects the Los Angeles River-Arroyo Seco Confluence), Los Angeles Union Station to Anaheim, and Los Angeles Union Station to San Diego. The southern route designs currently look at trestle bridging over the LA River, but of the 4 designs proposed through downtown northward through the Taylor Yard right of way, three now are tunneling options, where the trains would run 70 feet under the Los Angeles River. Design 4 which tunnels under the River and exits at the surface near the 2 Freeway and Fletcher Drive was a new proposal and finally one from HSR that seeks to complement rather than compete with LA River restoration activities in Cypress Park near the Rio de Los Angeles State Park and the new LAUSD high school.

The second top item was the presentation by Tori Kjer of the Trust for Public Land (TPL) on the LA River and Aliso Creek Confluence Project in the west San Fernando Valley, which creates a riverside greenway on a Los Angeles Department of Water & Power easement and a portion of a vacated street east of Wilbur Avenue and Kittridge Street. This project, which has already received partial grant funding, was unanimously approved by the Committee as its first project.  This project also includes the Rivers & Mountain Conservation Authority (RMCA) as a partner.

Other river projects underway incudes the Headwaters Project on Owensmouth Avenue in the West San Fernando Valley and the North Valleyheart Riverwalk in Studio City.

Committee member activity reports included the following:

USACE - There will be a federal site visit within the next couple weeks along the Ecosystem Restoration Study area of the LA River. The Corps will also be having a 'sweet spot' workshop with High Speed Rail in the new few weeks to work out final alignments along the River.

LA River Office - North Atwater Park and the Elysian Valley Bikeway both had successful groundbreaking and dedication ceremonies, respectively. Omar Brownson has been named as new Executive Director of the Los Angeles River Revitalization Corporation. There will be a public River Update meeting at 6:30pm on February 10th in Reseda, location to be announced. This year's Mayor's Day of Service on March 12th will focus solely on the LA River and project ideas should be sent to Carol Armstrong.

Bureau of Sanitation - The Low Impact Development Ordinance was approved by the LA City Council and is now at the City Attorney's office for review. The groundbreaking occurred for a new green alley at Vineland Avenue and Burbank Boulevard, which will recapture enough groundwater to serve 60 homes annually. The Avenue 19/Humboldt Pocket Park Stormwater Capture project is underway. A blighted alley in South LA at Manchester and Figueroa is being converted to a green groundwater project in cooperation with Caltrans. All these projects are efforts to comply with the TMDL Implementation Program.

Other updates included:

The proposed LA-Rio (Los Angeles River Improvement Overlay) Ordinance is now out of the City Attorney's office and back in Planning, where significant revisions are likely to comply with other recent ordinances including the Green Streets and LID Ordinances.

There will be no LA River federal advocacy trip to Washington this year. However, the Committee is hoping to hold meetings with local Congressional leaders and perhaps State legislators in March.

Proposed topics for the next meeting, scheduled for Monday, April 4th at 1:00pm include an update from the County on the Sediment Removal Plan and a request from FOLAR on River access. This meeting will be  held at the LA County Dept of Public Works, 900 S. Fremont Avenue, Alhambra, in the conference center there.

LA County Dumps on Oaks and Sycamores in Arcadia

In the latest version of 'your tax dollars at work,' the Los Angeles County Flood Control District intends to start to clear 11.3 acres of old-growth oak and sycamore trees in Arcadia to create a dumping area for tons of debris dredged from the Santa Anita Dam.

This planned action should alarm Southern California nature lovers for two reasons:

First, this effort destroys a historic plantation of trees whose growth has taken decades to achieve in an area quickly losing tree canopies.

Secondly, this plan sets a precedent that could lead to similar old growth tree destruction in the Hahamongna Watershed Park in Pasadena next year when the County uses 'emergency funds' from FEMA to remove 1.2 million cubic feet of sediment from behind Devils Gate Dam.

Fortunately, open space activist Christle Balvin and the Sierra Club 'got wind' of the County's plan and have requested a meeting with the County to discuss alternatives to this tree removal.

And they need your help, to prove to the County that these trees matter. They've arranged an 'inspection tour' of the sediment disposal site for Saturday, December 4th at 9:30am at the end of Elkins Avenue in Arcadia. This is a case where body count may be the difference in protecting tree count. For more information, call 626-476-7324.