From Acorns to Oaks

What do we see here looking down this plastic tube?

These are acorns collected from the Sunol Valley. For what you ask? We are planting over 150 Oak trees at the Calaveras Dam Replacement Project. As a commitment to the environment, the tree plantings are part of our mitigation to restore oak woodland at our project site. We are also committed to re vegetating all areas with annual grassland where oak woodland is not appropriate. 

Among the species being planted are the Coast Live Oak (Quercus agrifolia) and the Blue Oak (Quercus douglassii). Historically, oak trees are slow growing and can take as long as two to three decades before they begin to provide significant shade. Winter is an ideal time to plant to allow the tree to focus on root growth. 

Some oaks can send a tap root down as deep as five feet in the first year of growth. To help the acorns sprout, and to avoid being dug up by squirrels and birds, they are placed in the plastic tubes right into the ground. The tubes also protect them from hungry herbivores –like deer - and provide a great micro climate for the trees to thrive. 

The next photo shows our oak tree plantings in an area we are no longer working in, the left abutment of the dam, located at the Calaveras Dam Replacement Project. 

See you around the Valley!

Getting By with a Little Help From Our Friends

We do not need to tell you that now is the rainy season in Northern California. Some amphibians in the  Sunol Valley use the the wet season to move around from their burrows to breeding habitat and to find food.

Recently one of the workers at the Calaveras Dam Replacement Project spotted this California newt  passing through the construction site. On its back a Sierran Tree frog was hitching a ride. Who can’t relate to a time when you need a lift to get where you’re going?

Our workers are trained to spot wildlife like this and move them out of harm’s way for construction… hitchhiking or not.

Stay safe and dry out there! 

Heroes in a Half Shell at Calaveras Dam

We at the Calaveras Dam Replacement Project are constantly reminded that our construction area is someone else’s home. Case in point: the Western pond turtles (Actinemys marmorata). Our little heroes in the half shell are coming out of hibernation. A species of special concern in California, Western pond turtles prefer calm water with lots of things to bask on and plants to hide under.  They are opportunistic feeders and will eat pretty much anything they can reach and overpower, including aquatic plants, fishes, aquatic invertebrates and carrion if they can find it. They hibernate nearby in burrows or in upland areas until the temperature is nice, then they come out and head to the water to find food and mates.

Our construction workers spotted the first Western pond turtle of the season roaming on one of our haul roads. Given there are large vehicles (think trucks with wheels that are 9 feet tall), it was important to sweep this girl up and put her in a safe place away from the site. Our biological inspector Aaron Sunshine did just that at a pre-designated release site. On a daily basis, our environmental inspectors work closely with construction staff to identify any wildlife that enter the construction area. Our team works to protect the wildlife in the Watershed ensuring we keep these protected native species safe from harm while we build this important project.  

Maybe it was the luck of the Irish? Or just a good day for our Western pond turtle to be returned to a safe habitat. Aaron and his team will be keeping a sharp eye out! Happy St. Patrick's Day!

Peek-a-boo: Western pond turtle (measured at 16 cm carapace length) safely relocated at the Calaveras Dam Replacement Project by our project Environmental Monitor

Here is our Western pond turtle being released
safely back into the reservoir shoreline

California red-legged frog: Our Newly Famous Sunol Valley Resident

Just a few weeks ago, Governor Jerry Brown signed legislation designating one of our local Sunol Valley animals -- the California red-legged frog -- as the official State Amphibian! Since getting an autograph is out of the question, we thought we’d offer you a reintroduction to our famous resident instead.

The California red-legged frog is the largest native frog in the state and was first made famous in Mark Twain’s The Celebrated Jumping Frog of Calaveras County. According to the National Wildlife Federation, true to its name, they have reddish coloring on the underside of their legs and belly. They dine on anything they can catch and fit into their mouths. Mostly insects, but the occasional amphibian or small mammal might also become dinner. Speaking of dinner, California red-legged frogs were once a popular dinner cuisine during the Gold Rush era.

Contra Costa and Alameda Counties contain the majority of known observations of California red-legged frogs in the San Francisco Bay Area (U.S. Fish and Wildlife Service 2002). Today, their existence is threatened due to loss of habitat, particularly near urban communities and development. Thankfully, the 36,000 acres of Southern Alameda Creek Watershed lands owned by the San Francisco Public Utilities Commission has been protected and is a haven for our famous residents.

Our primary goal as watershed stewards is to protect existing populations, control non-native predators, and protect habitat for the red-legged frogs. As we make progress on our Water System Improvement Program in Sunol Valley, our Environmental Compliance teams work side by side with construction contractors to ensure our newly-designated Official State Amphibian is safe from harm.

Photos courtesy of Bill Stagnaro, Environmental Inspector
with the Calaveras Dam Replacement Project

Whales in the Sunol Valley?

Since construction began at the Calaveras Dam, team paleontologists have had some remarkable finds from ancient shark teeth to marine mammal vertebrae all collected during the excavation of over 4 million cubic yards of earth over the sediments that were once an ancient sea floor.  

Just this week, project paleontologists found a portion of an ancient whale skull in the slope above the spillway excavation of the new dam. The skull is almost a yard long and relatively intact, except for a small portion of the right rear section which is missing. Our paleontologists are still researching the find but initially assess the fossil to belong to a Mysticete (or baleen) whale, from the family of Humpback, Grey or Blue whales that live in the oceans today and forage on plankton. This fossil was discovered in the temblor sandstone formation which makes it over 20 million years old.

The project takes important steps to salvage these paleontological finds for educational purposes. The critical construction work to build a replacement dam has not been affected and continues, while we discover amazing fossils to add to the rich history of this valley.

Paleontologists Bruce Hanson and Jim Walker work on uncovering fossils at Calaveras Dam. Photo credit: Robin Scheswohl

In November 2013, a collection of bones including vertebra from a marine mammal were discovered on the lower portion of the Spillway.  It appears to show a complete cross section of the body, neural arch and measures 15 x 7 centimeters. Some of the other bones appear to be ribs. None of the specimens found interfered with construction activities and the specimen still remains in the rock.

Our Resident Bald Eagles

The land that we own in the Southern Alameda Creek Watershed has been protected for over a century.  By controlling the activities on our watershed lands, we ensure top water quality for our customers and preserve prime habitat for rare and endangered species. The 36,000 acres the SFPUC owns have become an oasis.

These lands are home to all sorts of plants, insects, and critters, including the Most Beautiful Jewel Flower, Callippe Silverspot Butterfly, California Tiger Salamander, California Red-Legged Frog, Alameda Whipsnake, Golden Eagles, and not one, but two nesting pairs of Bald Eagles.

Interestingly, both eagle pairs nest not far from our ongoing construction projects at Calaveras Dam and at the habitat restoration project at San Antonio Reservoir.

Our environmental teams monitor the eagles’ success annually and establish a wide “No Disturbance” boundary around the eagle nests, in coordination with the US Fish and Wildlife Service and California Department of Fish and Wildlife, to avoid aggravating nesting bald eagles. During nesting season, teams closely monitor the eagles’ activity around both reservoirs to ensure our construction work does not affect nesting birds. We go to great lengths to ensure that these special animals continue to thrive.

 

We are proud to announce that the eaglets (two at Calaveras and two at San Antonio) of both eagle pairs are very close to fledging!  The young eagles will continue to receive care from the parents for a while before exploring new territories on their own.  The parents – soon to be “empty nesters”  – will likely stay in the neighborhood to take advantage of the plentiful food source and relative isolation and protection the southern Alameda Creek watershed provides.

Calaveras Reservoir Bald Eagles
Photo permission courtesy of Tam Phan

Calaveras Reservoir Eaglet takes flight
Photo courtesy of Bill Stagnaro, Environmental Inspector

Environmental Compliance Manager Cullen Wilkerson and Specialty Environmental  Monitor Aaron Sunshine survey our Bald Eagles

Calaveras Reservoir Eaglet soars through Sunol Valley
Photo courtesy of Bill Stagnaro, Environmental Inspector

For more project information, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Fascinating Fossil Finds at Calaveras Dam

Every day, our scrapers dig soils and earthen materials to make room to build the replacement Calaveras Dam.  We have special staff who monitor high sensitivity areas during construction searching for paleontological and cultural resources, which are protected by federal and state laws.  Construction crews also attend environmental training about the identification and protection of paleontological and cultural resources. Calaveras Dam project teams have discovered fascinating finds within our construction site. 

What are Paleontological Resources?

Paleontological resources include: remains of prehistoric/extinct plants and animals, petrified wood, fossil leaves, fossil remains of vertebrate and invertebrate organisms, fossil tracks and track ways, and plant fossils, typically of Pleistocene Epoch (> 12,000 years ago) or greater age. 

What have we found?

Fossilized plants such as wood, leaves, and a pine cone have been salvaged from the site.  Invertebrates uncovered include: scallops, clams, snails, barnacles and worms.  We have also found shark teeth that are still being analyzed but may be related to a great white shark although much larger (Think “Jaws” and then some).

Our most fascinating finds are linked to prehistoric marine mammal(s).  This includes an intact portion of a backbone of a whale.  These finds are still being analyzed by experts.

Why?

Most of the fossils have been found in the 20 million year old marine sandstone called the Temblor Formation.  The Sunol Valley area was below sea level in the Pacific Ocean about 20 million years ago and has since been uplifted along with the rest of the Coast Ranges. Life along the old coast was similar to today, with abundant clams, mussels, sea worms and other invertebrate organisms living in the sand. But the fossils also document significant differences from today’s relatives and provide important information about the details of evolution and environments of the plants and animals represented by the fossils.  We continue to work to preserve and protect these neat findings every day.

Fossils & Shark Teeth discovered at the Calaveras Dam Replacement Project Site

Air Monitoring Program Continues at Calaveras Dam

If you are traveling on Calaveras Road, you may notice what appears like chain link cages along the side of the road. These are our air quality monitoring stations.  These stations have been placed throughout the valley and within the construction boundaries of the Calaveras Dam Replacement Project.  Our teams collect air sampling data throughout the week at the various stations to ensure we are protecting the public and our workers at all times. 

Why are we doing this?

Portions of the approximately 7 million cubic yards of material which is being moved to construct the replacement Calaveras Dam contain rock formations that contain varying levels of Naturally Occurring Asbestos.

Geotechnical explorations in the area of the Calaveras Dam Replacement Project construction revealed that the Sunol Valley contains rock types that are known to contain naturally occurring asbestos and metals.  Serpentinite rock (“California Jade”) is the state rock of California and occurs naturally in at least 44 of California's 58 counties.

The SFPUC has implemented an extensive air monitoring program that is designed to keep dust generation to a minimum while assuring that asbestos-containing dust does not leave the site at levels sufficient to pose unacceptable risks to individuals who may work, recreate, or reside in the vicinity of the site.

For more information about our air quality monitoring and to see the latest air monitoring results, visit our NOA Website by clicking here.  Our results are updated weekly.

Our Staff collecting samples from an air monitoring station

Meet David from our Calaveras Dam Air Monitoring Team
working at one of our air monitoring stations

Calaveras Critters on the Move!

If the television show Unlikely Animal Friends were to film an episode at the Calaveras Dam Replacement Project, they would have no trouble identifying symbiotic animal relationships all over the Southern Alameda Creek Watershed. Our personal favorites are ground squirrels and the threatened California Tiger Salamander.

Tiger Salamanders live underground in the burrows of other animals, quite often the burrows of ground squirrels. When the rains come to the watershed, the California Tiger Salamanders leave their burrows and make a beeline for a nearby pond where they can meet a mate and lay eggs. 

Problem is, there is a large dam construction project in the way. Our biologists placed tubs at strategic locations around the site. As they walk the perimeter of the project on a daily basis, they take the captured salamanders and relocate them to pre-designated places offsite. 

They often make sure to stick the Tiger Salamanders into ground squirrel burrows that are stable.  The ground squirrels do not seem to mind their amphibious neighbors, and provide the added benefit of digging out the tunnel should it collapse. Otherwise the salamanders would be trapped by cave-ins and might perish. Who knew?

Photo courtesy of Pete Trenum, Elkhorn Slough



For more project info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Calaveras Dam Replacement Project - Winter Update

Project Update

In mid- June of 2012, during excavation of the large hill known as “Observation Hill” on the left side of the valley (if you are looking downstream, standing with your back to the reservoir), the Contractor encountered unexpected geologic conditions that could contribute to the instability of the left abutment and spillway area as designed.  These features were not visible at the ground surface, and were not apparent during the extensive pre-construction geotechnical investigations. Therefore, the excavation cut slope in “Observation Hill” has been re-designed to “lay back” the slope to a flatter slope in order to produce a final slope that will be stable during construction and over the entire life of the new dam.

What this Means

1)    Additional Materials to Move - Approximately 3 million cubic yards of additional material that was not originally anticipated now needs to be excavated and moved to disposal sites around the reservoir. We are working with the environmental regulatory agencies to secure disposal sites for these materials within the designated construction areas. No additional materials will be hauled off site on public roads.

2)    Extended Construction Schedule - Because of the additional time needed to excavate these additional materials, we anticipate a 25 month delay in the project, which would put the completion of construction activities at the end of 2017.

3)    Impact to Project Cost, not to WSIP Overall Cost – Based on preliminary projections, the cost of the project will increase by approximately $133 million. These additional costs are offset by savings recorded on other projects and favorable bond financing so the overall Water System Improvement Program (WSIP) is still forecasted to be completed within the currently approved budget of $4.6 billion.

4)    Calaveras Road Shutdown Delayed - The second scheduled closure of Calaveras Road will be postponed until 2014, at the earliest. The duration of the closure remains 18 months, Monday through Friday only, but the specific dates will be determined when the contractor completes re-sequencing of the construction schedule.  We will notify you in advance of the closure period.  Join our road closure notification mailing list by emailing: mle@sfwater.org or calling our 24 hour answer hotline at (866) 973-1476.

Environmental Review

We are currently working with the regulatory agencies to amend the permits for these changes. The San Francisco Planning Department will distribute an Addendum to the Final Environmental Impact Report in mid-December 2012. To obtain a copy of the Addendum, please visit www.sf-planning.org, or contact: Chris Kern, San Francisco Planning Department at (415) 575‐9037 or email at chris.kern@sfgov.org.

Project Background

The San Francisco Public Utilities Commission, owner and operator of the Hetch Hetchy Regional Water System, is building a new dam to replace the existing Calaveras Dam in the Sunol Valley. Calaveras Reservoir, impounded by the Calaveras Dam, is our system’s largest drinking water reservoir in the local Bay Area. When full it provides more than half of our Bay Area storage capacity for 2.6 million customers. The existing earth fill dam is 87 years old and is located within 1,500 feet of the Calaveras earthquake fault. In 2001 we lowered water levels in the reservoir to less than 40 percent of normal operating capacity in response to seismic concerns.   The Calaveras Dam Replacement Project is the largest project of the $4.6 billion Water System Improvement Program (WSIP) to repair, replace, and seismically upgrade key components of the Hetch Hetchy Regional Water System.

Work Completed to date

Construction began in August 2011 to build a new earth and rock fill dam adjacent to the existing dam. Since then, the Contractor has moved nearly two million cubic yards of earth and rock materials to make room for the new dam. Crews have prepared disposal sites, constructed a soldier pile tie-back wall to stabilize a landslide in the right abutment (the right side of the valley as you face downstream from the dam, away from the reservoir), and began injecting cement grout deep into the joints in the rock of the dam’s foundation. The team has excavated to the new dam’s foundation and has started to build the new dam. In addition, we have begun construction of connecting outlets from the reservoir, and successfully completed the first 2-month closure of Calaveras Road in spring 2012.  However, there is still a great deal of work that lies ahead, with the project only 26% percent complete as of November 2012.

For more project info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org 

We are Building a “Mini-Dam”...for the California Tiger Salamanders!

Prior to and during construction, the Calaveras Dam Replacement Project implements measures to avoid and minimize impacts to wildlife located in the Alameda Creek Watershed. 

Our Environmental team has taken proactive steps to protect and relocate the California tiger salamander (Ambystoma californiense) species since the start of the project.  The California tiger salamander (CTS) is an amphibian native to Northern California growing up to 8 inches long.  CTS have started to migrate at night from upland habitats to aquatic breeding sites, especially during the first major rainfall events of fall and early winter.

 California tiger salamander (Ambystoma californiense)

Wildlife exclusion fencing is strategically located along the boundaries of the construction work limits to deter wildlife from entering.  Also, water moistened buckets are placed in trenches between silt fences to catch the critters, which are later relocated to nearby ponds.

Just this week our approved biologist monitored berm repairs performed on a relocation pond for CTS.  The berm serves as a barrier which is positioned on the top of the pond, to reduce turbidity and maintain suitable conditions in the pond.  Permission was given by the California Department of Fish and Game to relocate 50 CTS to this location. 

As of today, 78 California tiger salamanders have been trapped and relocated to safer habitats away from project construction. With the repaired pond, we will be able to provide them a suitable and safe environment for breeding.

For more project info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org.

Repair work on Pond for California tiger salamander

Repair work on Pond for California tiger salamander

Photo of pond after work completed

Protecting Migratory Birds at Calaveras Dam

Over the last 100 years, the state’s migratory bird populations have declined due to loss of habitat.  Here at the Calaveras Dam Replacement Project, our teams make great strides to protect the population of our migratory birds.

Nesting season generally falls between February 15^th to August 15^th for most species. Our Environmental team performs focused surveys for active nests prior to the start of construction activity.  The staff survey for active nests of migratory birds and protected raptors, such as the Bald Eagle. 

Bird nesting deterrents such as reflective signs are also placed near or on construction equipment to prevent birds from nesting near work.  When active nests are found, our teams immediately place disturbance-free buffers around the active nest until the young have fledged successfully.  This year, a Bald Eagle pair successfully produced eagle chicks away from the Calaveras Dam project site at the nearby PG&E tower. 

For more project info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Our Bald Eagle nest at the PG&E tower

Some bird species, such as the Black Phoebe shown above, nest on construction equipment. The equipment was monitored and remained unused until the nestlings fledged. 

Photos courtesy of Bill Stagnaro & Cullen Wilkerson, Calaveras Dam Project Environmental Team

Tarantula Crossing

Fall is tarantula time at the Calaveras Dam project site. The annual ‘tarantula migration’, which, begins in September through end of fall, is underway. Normally shy, living underground in burrows, and nocturnal, these hairy spiders are making their yearly journey above ground. The male tarantulas are migrating across our lands in search of female tarantulas to breed, and then the males scurry home in fear of being eaten by their new female companions. As part of our continuing efforts to protect wildlife, you will see many of our workers driving slow enough to stop and let the hairy critters cross the road, evident in this photo taken by our staff.

These hairy, eight-legged creatures have been feared by many. In reality, tarantulas have never caused any human deaths and are only dangerous to small insects. Tarantulas have very small venom glands and the bite of our tarantula is compared to a bee sting. Harmful spider bites generally come from poisonous spiders of other species. Although we wouldn’t want to find them inside the office trailers, we’re glad to yield to them on the roads outside.


For more info, contact us at our 24 hour answer line at (866) 973-1476 or email mle@sfwater.org

Photo courtesy of Bill Stagnaro, Environmental Inspector & Biologist

Sustaining the Environment at the New Irvington Tunnel

The seismic upgrade and expedited delivery of the New Irvington Tunnel is crucial to maintaining a consistently reliable, high-quality water supply for 2.5 million Bay Area residents. Engineers and construction and mining professionals work daily to achieve this goal. The San Francisco Public Utilities Commission (SFPUC) is equally committed to remaining environmentally responsible, and is working in collaboration with environmental scientists to ensure the work is done in a timely manner and environmentally sustainable manner.

Before construction could begin at any of the three tunneling sites, the SFPUC took numerous measures to ensure that environmental impacts are kept to a minimum on the project sites. One measure used to protect wildlife is to install wildlife exclusion fencing around each of the work sites. The black 4-foot high fabric fencing deters wildlife from entering the construction sites and is monitored for its integrity on a weekly basis.


The fence won’t discourage all wildlife. For our winged neighbors, an environmental monitor scours work sites for any signs of nesting birds. Initially, monitors try to discourage birds from establishing nests on site. However, if they encounter a completed nest, construction zones are altered or activities are postponed in that area until all the nesting birds have fledged or left the nest.

Protections against erosion and storm water run-off are also required. On the exposed slopes at all three tunneling sites, workers laid down wattles ( which are woven netted tubes filled with straw) to help prevent soil erosion. Wattles are laid down perpendicular to the slope, and when combined with other practices (such as mulching), prevent or slow down the effects of stormwater runoff.

Mulch is also applied to the hillsides to prevent erosion, through both a process called hydro-mulching and by manual methods. Hydro-mulch, which consists of recycled natural fibers combined with a tackifying agent, is sprayed onto the hillside and coats the soil. Straw is also manually laid down onto the slope. To help the vegetation grow, seed is added to the mulch mixture and applied to the slope through a process called hydro-seeding. As the vegetation grows, the mulch decomposes into the soil and the vegetation itself stabilizes the slope and prevents rain from directly falling on the soil and producing erosion.


Finally, all three of the tunneling sites are monitored daily by SFPUC environmental inspectors and specialty monitors. They verify that workers are in compliance with the environmental standards set by the SFPUC and environmental permitting agencies to maintain a healthy environment!