Saturday, January 26, 2013

Sloat Beach Fill Time Comparison - Fall 2012 to Spring 2013

<Updated March 16, 2013>

In the summer/fall 2012, the National Park Service and City of San Francisco implemented a sand management project at Ocean Beach, which moved excess sand from north Ocean Beach and placed it along an eroding section of beach/bluff at Sloat Boulevard.

The project was completed in September 2012 and resulted in the placement of approximately 100,000 to 150,000 cubic yards of sand in front of the parking area at Sloat.

I've visited the area several times over the past few months and have taken photos to document the evolution of the sand fill.  Since October, a significant portion of the sand has been eroded due to high waves during the late fall and early winter months.  The most significant retreat appears to have occurred at the south end of the parking lot, in the vicinity of the sand bag to revetment transition.

I first noticed exposure of the sand bags in November 2012.  My visit in January 2013 was the first time I had observed exposed rock, which must have been exposed sometime over the past month. Upon my return in March 2013, it appeared that additional sand had been placed over the sandbag embankment at the south end of nourishment area.

While the sand has been actively eroding, the good news is that it has temporarily prevented the need to place additional rock on the beach under emergency conditions, which has been the standard operating procedure over the past few years.

Read more about the project here and on the NPS project page.

Here's a video of some of the erosion processes at work, from November 2013:

October 2012 to January 2013 to February 2013 to March 2013. View looking south at Sloat Blvd parking lot.

October 2012 to December 2012 to January 2013 to February 2013 to March 2013. View looking north from south end of Sloat parking lot.

October 2012 to February 2013. View looking north at Sloat parking lot.

 January 2013 to February 2013. View looking north towards Sloat parking lot.

October 2012 to February 2013 to March 2013. View looking north at Sloat parking lot.

December 2012 to January 2013 to February 2013 to March 2013. View at south end of parking lot. Sandbag to revetment transition.

October 2012 to December 2012 to January 2013 to February 2013 to March 2013.  View looking south along beach.

October 2012 to December 2012 to January 2013 to February 2013.  View looking north along beach.

Monday, January 14, 2013

The ONE movie you should see this year

There is one movie you should see this year and it won't be nominated for an Oscar. You probably won't guess what it is and have probably never heard of it, so I'll just go ahead and tell you. The movie is called "Rebels with a cause", by Nancy Kelly and Kenji Yamamoto . Here's just a few reasons why you need to see this film:

Rodeo Lagoon, Marin County

Tomales Bay, Marin County

Marin County Open Space

Point Reyes National Seashore, Marin County

Drakes Beach, Point Reyes National Seashore, Marin County
The Marin that could have been... San Francisco's Seacliff Neighborhood. (c) Kenneth and Gabrielle Adelman.

The film tells the incredible, somewhat unknown, story of the creation of the Point Reyes National Seashore in western Marin County, CA. Starting in the late 1950s, the film chronicles a series of political and environmental battles over proposed developments, highways, resorts, and planned communities that would have transformed the natural landscape into a concrete covered suburban sprawl.

Through the tireless efforts of conversationists, the Point Reyes National Seashore was established in 1962 and represented a new vision for the park service - a national park near an urban center. Further, the park preserved the historical agricultural land use for the ranchers as a "Pastoral Zone" - which is still active today.

The actions of environmentalists in the 1960s paved the way for the establishment of the Golden Gate National Recreation Area, signed into law by none other than Richard Nixon in 1972. Again, the park service broke the mold, acquiring land no longer in use by the Army to establish a unique non-contiguous national park around San Francisco, initially comprised of Alcatraz, Fort Mason, and the Marin Headlands.

The spirit of the early conservationists in Marin spread through California, defeating other development projects and freeways as well, such as the Devils Slide bypass south of Pacifica, which would have run a freeway right over the top of Montara mountain. This year, the voter-supported tunnel alternative will finish construction and the old Highway 1 grade across Devils Slide will be converted into a park and coastal trail. 

Conservation work continues in the Point Reyes area today by groups such as the Point Reyes National Seashore Association and the Marin Agricultural Land Trust

It's great to reflect on the rich conservation history here in northern California and develop a deeper appreciation for the open space that we have. But we're not out of the woods yet and this isn't only a California story. Development and suburban sprawl still threatens so much of our natural landscapes all over the country. Whenever I return to my home state of Virgina I notice a new housing development, or a freshly cleared area devoid of trees. I'm not saying that all development is bad, but pay attention to what is going on around you!  It's a slow piecemeal process - a few houses here, a new shopping center there - but pretty soon you'll look around and start to forget what the view once looked like.  

Packed house at the screening of Rebels with a Cause at Point Reyes Station. January 13, 2013.

Find out more in Saving the Marin-Sonoma Coast, by L. Martin Griffin.
Visit the Rebels With A Cause Facebook page or on the KRCB website.

Sunday, January 6, 2013

Rainy day at Point Bonita Lighthouse

After six years of living in San Francisco, Allison and I decided it was finally time to visit the newly re-opened Point Bonita Lighthouse in the Marin Headlands. The lighthouse is still in use for navigation and is operated by the U.S. Coast Guard. The National Park Service provides access to visitors and a very knowledgeable docent was on hand to tell us about the history of the lighthouse.

We parked up by the YMCA and walked down to the lighthouse on a nice path. It was a gloomy day but the weather was calm and we enjoyed iconic views of San Francisco, the bay, and the ocean on our way down to the point.

The path winds its way down the hill and traverses a narrow ridge flanked by water on both sides - San Francisco Bay to the east and the vast Pacific Ocean to the west.

The lighthouse is shielded from view by the rocky point for much of the walk and the steep terrain is negotiated by a narrow dark tunnel. According to my Hayes and Michel book, the lighthouse is perched atop an extensive outcrop of pillow basalts of the Franciscan Complex, formed around 150 million years ago by the cooling of underwater eruptions of lava - pretty cool. A park ranger emerged from the darkness at just the right time to tell me not to walk on the outside of the railing. Oops. 


After waiting a few minutes in the dark there was enough of a break in the traffic to snap this photo from inside the tunnel.

Coming out of the tunnel we finally got a view of the lighthouse perched out on the point! Only a short treacherous section of crumbling rock was left to negotiate. Luckily a sturdy suspension bridge led the way.

Before crossing the bridge, we checked out the view a bit. I accidentally caught this couple embracing on the leeward side of the lighthouse, sheltered from the wind.

The final approach to the lighthouse is guarded by a suspension bridge which re-opened to the public in April 2012. It may have been my imagination, but it sure felt like the bridge bounced and swayed as we made our way across the 140 ft span.

A small museum is open in the lower level of the light tower and was staffed by a NPS docent. According to the docent, the lighthouse was originally built in 1855 up on the bluff immediately north of the point, but was often obscured by the fog and not visible to mariners due to its height 300 ft above the ocean.

In 1877, the lighthouse was moved to its present location on the point, which improved navigation through the Golden Gate somewhat; however, passage was still dangerous. For many years, mariners had only three points of navigation to guide them through the Gate: keeping Point Bonita to port, Fort Point to starboard, and aiming for Alcatraz. Needless to say, many ships ran aground on the dynamic shoals and rock outcrops.

The rain picked up a bit while we took shelter inside but we eventually braved the weather and headed back to the car, glad to have finally checked out this historic landmark!

Info from the NPS brochure: Point Bonita Lighthouse is reached by a half-mile trail that is steep in parts. Mid-way along the trail, a tunnel allows access to the lighthouse only during visiting hours: Saturdays, Sundays, and Mondays from 12:30 to 3:30 pm.