Remembering Loma Prieta – And Preparing for the Next Big One

Monday, October 17^th is the 27^th anniversary of the Loma Prieta Earthquake. The 6.9 magnitude quake shook the earth for 15 seconds, took the lives of 67 people and injured almost 3,000 more. There was an estimated $6 billion in property losses. We here at the San Francisco Public Utilities Commission have been preparing for the next big quake ever since.

As the owner and operator of the Hetch Hetchy Regional Water System that serves water to 2.6 million people in four Bay Area counties, we have worked for more than 10 years to repair, replace, and seismically upgrade vulnerable portions of this system as part of the $4.8 billion Water System Improvement Program (WSIP). The program itself is more than 90% complete. Our water system is safer and more reliable today than it was 10 years ago, let alone 27 years ago. Our promise is that we can deliver minimum demand to our customers within 24 hours after a major earthquake. We can make good on that promise because of WSIP.

Here’s just a few reasons why:

* The Bay Tunnel is a seismic lifeline carrying water under San Francisco Bay. It was brought into service on time and under budget in October 2014.

* The New Irvington Tunnel carries water between our East Bay and Hetch Hetchy supplies and our Bay Area Customers. Located between the Calaveras and Hayward Earthquake faults, this seismically designed tunnel allows us to take the existing 88 year-old tunnel out of service for maintenance.

* A new Bay Division Pipeline #5 connects to both of these new tunnels in the East Bay and on the Peninsula to provide greater delivery reliability to our customers. It replaces two pipes that were constructed in 1926 and 1935.

Wait, that’s not all!

Our Harry Tracy Water Treatment Plant treats water from the Crystal Springs and San Andreas Reservoirs for more than one million customers in northern San Mateo and San Francisco counties. Upgrades at the plant include new filters, a new 11 million gallon treated water reservoir, and various other hydraulic, mechanical and electrical upgrades. The Harry Tracy Water Treatment Plant can now reliably provide 140 million gallons of water per day, for 60 days within 24 hours of a major earthquake.

 

The new 11.5 million gallon treated water reservoir is one of the improvements at the Harry Tracy Water Treatment Plant on the Peninsula.

Our Peninsula customers are served by several large water transmission pipelines, some of which are the oldest and most crucial parts of the system. The Peninsula Pipelines Seismic Upgrade Project addressed this issue by upgrading the most vulnerable portions of several of these pipelines.

 

 

Crews install a pipe segment in the Peninsula to improve the pipeline’s reliability, especially during an earthquake.

This work is never done. We will continue to replace and upgrade our system pipelines, pump stations, and treatment plants even after the WSIP is complete. We’ll worry about your water so you won’t have to.

Life on the Watershed: Dragonfly Weather

                                                    Flame skimmer

The Peninsula Watershed  is home to a wealth of different insects, including colorful dragonflies that can be drawn out on warm fall days to hunt and feast on other insects. 


Watch too for migrating birds doing the same thing as they pass through on their way south.  


                                                                                        Yellow warbler        
                                                                                                                                                                                                                                                                                                                                                                                                                                                           
                                                                                                                

New Grasslands Coming near Sawyer Camp Trail

                                      Spraying the hydroseed mix of native seed, wood fiber, tackifier and water. 

This week our habitat restoration crews began hydroseeding newly opened areas above the southern half of the Sawyer Camp Trail.

The young native serpentine grasses will begin sprouting within a couple of weeks, and be well established by next spring-- assuming some rainfall and other favorable conditions. We’ll keep watch for regrowth of the invasive acacias for the next year or two, and then plant acorns for future native forests.

The approximately 20-acre replanting in the Sawyer Camp Trial vicinity is part of a larger restoration project to bring back about 180 acres of native oak woodland and grassland at several different Peninsula Watershed locations. The historic habitats provide essential food and shelter for a variety of native plant, butterfly, bird and other wildlife species (some found nowhere else in California).

The fresh young plantings will be steadily maintained by our staff to promote healthy establishment, and we'll monitor their performance for several years after that.   

Watershed's Oldest Dam Still Going Strong

It was San Francisco’s first water source outside City limits. 

Pilarcitos Dam—situated deep in the Peninsula Watershed’s remote Pilarcitos Canyon—turned 150 this year. It survived the earthquakes of 1906 and 1989 with no damage, it’s still in service today, and planning is under way to extend its operating life for years to come. 

Today, the 1866 earth-fill dam holds Pilarcitos Creek raw water for delivery primarily to the Coastside County Water District in Half Moon Bay, with some water also diverted as supplemental supply to Lower Crystal Springs Reservoir. Water releases from the dam also improve downstream fish habitat, and the secluded woodsy canyon is a safe haven for nesting Marbled murrelets.   

Life on the Watershed: Watch for Baby Snakes along the Sawyer Camp Trail

It’s been called “one of the most beautiful snakes in the U.S.”

And the early fall is when the endangered San Francisco garter snake numbers are on the rise, with females giving birth to about 16 young each.  The baby snakes are about 5 to 7 inches long at birth, the ones that survive will reach adulthood at age 2, and they can grow to about 3 feet in length.

The protected San Mateo County species travels between vegetation or burrows and nearby bodies of fresh water (such as Crystal Springs Reservoir). Its favorite food is the tree frog, but it also likes other amphibians, including bullfrogs and the California newt, which is poisonous to most earth species.

The San Francisco garter snake is not dangerous, and—if you’re lucky enough to encounter one along the trail some September day—chances are it will slither away to safety quickly.  So watch it while you can!

Photos 1 and 2 by Elizabeth Larsen, USFWS.

Gathering and Sowing Native Seeds

Here crews are harvesting hayfield tarplant –a common native grassland species--near the eastern shore of the Lower Crystal Springs Reservoir. They will be part of a special seed mix that we’ll disperse nearby to help restore habitat later this fall when the soil is wet from the first rains and the weather is cool. 

  

Other native grass and forb seeds we’ve been collecting for the mix include yarrow, yampah, tufted hair grass, and Crystal Springs lessingia. We use locally harvested seeds for our new habitat sites whenever possible because they are so well suited to our watershed’s unique climate, soils, and hydrological conditions .

Later this fall, watch for the displays of Crystal Springs lessingia. Though rare, it happens to be abundant on our watershed’s serpentine grasslands, where it produces swathes of pink or lavender along I-280 when it flowers in the fall. 

                                Crystal Springs lessingia in bloom.

The removal of non-native trees and understory plants continues along the mid-section of the Sawyer Camp Trail through October. We’ll be hydroseeding those newly opened areas with native serpentine grass seeds too—and acorn plantings will follow.   

Life on the Watershed: The Return of the Bald Eagles

A breeding pair of  Bald eagles returned to the watershed this year and has successfully reproduced again. Three healthy eaglets—the largest number yet—fledged this year. 2016 was the fourth year in a row that the pair had nested on the Peninsula Watershed. 

“They were missing from San Mateo County for more than 100 years,” according to watershed keeper Sarah Lenz. “Our watershed has the land and resources to provide a good home for them and allow their chicks to sustain themselves and thrive.”

“It’s a testament to how we preserve the habitats that give wildlife a chance to stay wild without pressure from humans,” watershed keeper Peter Panofosky added.

Though the eaglets have left the nest area, they will continue to fly and hunt in the general vicinity. 

Our 2016 Crystal Springs eaglets will keep their brownish mottled color for the next few years before they acquire the distinctive white head at age four and full maturity. One or more could return as adults to start another nest in the protected lakes of the watershed.

Bald eagles mate for life, and—because they live up to 30 years in the wild—chances are that more eaglets will begin their own long lives on the Peninsula Watershed in future years.