Friday, October 30, 2009

Arroyo Seco USACE Study & Station Fire Update

I can't believe that it's been over a month since I've blogged on the Arroyo Seco, so I hope you have been following my regular tweets (@ArroyoLover) and Facebook (Meredith McKenzie) updates.

A lot has been going on along the Arroyo Seco Watershed ~ some good news, some not so good news ~ which is why I chose to post a bucolic picture of the Arroyo Seco in happier days, courtesy of the Arroyo Seco Foundation (

Let's start with the good news (and it IS good news)! The United States Army Corps of Engineers has announced that it will be a receiving approximately $224,000 in federal funding to move forward with the assessment phase of the Arroyo Seco Restoration Feasbility Study, which has been languishing since 2002 due to lack of funding. In addition to this direct funding, the Corps is obtaining another $125,000 in stimulus and carry-over funds that will give it a total of $350,000 to use for the study this fiscal year. This means that by September 2010, the F3/Assessment of Existing Conditions portion of the Study should be complete. This will lead the way for the F4 study phase delineating Potential Opportunity Sites/Proposed Design Components for habitat restoration. The 2002 Arroyo Seco Feasability Study, a joint project of the Arroyo Seco Foundation and Northeast Trees, offers a great foundation for the current Corps Study:

The not so good news is that now that the dust is settling (and sadly, blowing around) from the Station Fire, the largest in Los Angeles County history, the damage to the Arroyo Seco watershed is daunting: over 90% of the watershed burned and the healing of natural habitat and water quality may take up to 10 years to return to some semblence of pre-fire conditions. In the short term, the danger is the prospect of extensive mudslides, high ph factor in the water, and fast-moving debris flows rushing down the canyon into heavily populated neighborhoods along the river's perimeter. Fire emergency officials have identified and met with residents of over 40 homes whose properties are in extreme danger of impact from possible canyon mudflows.

In a worst case scenario, it's been projected that 1.9 cubic yards of sediment could reach the Hahamongna Basin just south of NASA's JPL facility. If this occurred, sediment capture in the basin would completely fill the spillway area of Devil's Gate Dam. While no one is predicting that this dire situation will occur, these numbers are instructive of the total potential sediment load coming off the mountain because of the fire aftermath 'scorched earth' condition.

The Angeles National Forest is closed indefinitely and USFS continue to ask hikers and others to refrain from curiosity walks along the perimeter. The extremely 'soft' footing due to erosion and ash build-up has already led to one rescue of one experienced hiker who slide deeply down a canyon when the trail unfoot literally gave way due to the post-fire conditions.

With the rainy season approaching, a special communications effort has been created by the Coordinated Agency Recovery Effort (CARE) which includes Los Angeles County Public Works, the US Forest Service, the US Geological Survey, the National Weather Service, Caltrans, LA County Fire, and LA County Sheriffs Departments. CARE operates out of the Public Works headquarters in Alhambra.

The role of CARE is two-fold: to keep communities informed about the County and Caltrans road system through the burn area and to continue to educate residents about what they can and should do to protect themselves and their property against mudflows.

The CARE website: features dozens of links with information and resources on fire recovery and debris flow preparation. CARE is also hosting 24 council/community meetings throughout the fire-affected and at-risk neighborhoods.

In addition, CARE will be establishing Facebook and Twitter accounts to provide real time updates to communities and residents during critical storm conditions. CARE also is distributing the Homeowner's Guide for Flood, Debris and Erosion Control to those living in designed at-risk areas.

For all of us Arroyo lovers, this winter will be one of helping the Arroyo by staying out of the Arroyo, assisting our neighbors and friends with emergency evacuations, and cooperating with police and fire personnel as directed.

Together, we can help the Arroyo Seco heal by respecting nature's process and leaving it alone, including limiting our outdoor recreational activities to safe, unburned sections along this beautiful canyon stream.

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