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MMWD Blog: Think Blue Marin

Welcome to our blog! Written by staff at MMWD, “Think Blue Marin” explores all things water in south and central Marin—water supplies, conservation, new projects, watershed management, and more.

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May 13

Happy 100th Birthday, Alpine Dam!

Posted on May 13, 2019 at 9:06 AM by Ann Vallee

Alpine Dam under construction in 1918

 Alpine Lake Jan 2017
Nestled deep in MMWD’s beautiful Mt. Tamalpais Watershed, Alpine Dam continues to play an integral role in supplying clean, local water to our customers—a full century after its construction.

Even at 100 years old, Alpine is not the oldest dam in our system. Both Lagunitas (1872) and Phoenix (1905) were built before MMWD was established. After MMWD’s creation in 1912, one of the water district’s first actions was issuing a $3 million bond to build Alpine Dam to serve Marin’s growing population. Today, replacing the dam would cost an estimated $200-$300 million.

Work on Alpine began in the summer of 1917, but the outbreak of WWI caused difficulties for the contractor as labor and supplies became difficult to secure. MMWD took over construction in January 1918, completing work in January 1919. Alpine was dedicated in a dam-top ceremony on June 21, 1919.

Alpine is unique among MMWD’s seven dams as the only concrete one in our system (all the others are earthen). When it was built, the dam contained 27,719 cubic yards of concrete and held just over a billion gallons of water. The dam was raised in 1924 and again in 1941 to its current capacity of nearly 2.9 billion gallons—about 11% of our total water storage capacity.

Originally, water from Alpine traveled via gravity through Pine Mountain Tunnel and miles of concrete pipeline, then on to customers’ homes and businesses. Today, water from the lake is pumped up to Bon Tempe Reservoir for treatment at Bon Tempe Treatment Plant before supplying the southern part of our service area. When Alpine is full, water flows over its dramatic spillway and into Kent Lake. From there the water can travel on to San Geronimo Treatment Plant, or it can be released to support fish and other wildlife downstream in Lagunitas Creek. Alpine thus remains at the heart of our water supply system. Along with maintaining our pipes and storage tanks, taking care of Alpine and our other reservoirs is critical to ensuring a reliable water supply for the next 100 years and beyond.
Apr 23

Garden Tour Sneak Peek: The Art of Lawn Replacement

Posted on April 23, 2019 at 9:40 AM by Ann Vallee

Garden Tour Preview This quaint garden in Fairfax proves that good things really do come in small packages! An exceptional example of a turf replacement project, its balance of landscape and art is truly inspirational. 

Interested in taking advantage of the State of California’s Turf Replacement Rebate, owner and professional landscaper Teliha decided to transform the previous lawn into a beautiful spiraling pathway. Matching the theme of mosaics found throughout the garden, each recycled stone is individually decorated with unique clusters of patterned tile or recycled beads, and the pathway is set in sand to make it permeable. Also replacing part of the lawn are native, low-water-use plants and a few veggie crops. Along the lower section of the garden is a creative solution to keeping unwanted visitors at bay: Swathed in vibrant wisteria vines, a column and cable retaining wall keeps deer out without sacrificing the view.

On the day of the Eco-Friendly Garden Tour, May 4, Teliha will be giving a presentation called "The Art of Lawn Replacement" at 11 a.m. and 2 p.m.—definitely one not to miss! Don't forget to register for the free tour to see this beautiful garden in person and to learn more about lawn replacement techniques.
Apr 22

Infrastructure Investments Help Ensure Clean, Reliable Water for the Future

Posted on April 22, 2019 at 3:36 PM by Ann Vallee

sgtp for blog
Constructed in the 1950s, San Geronimo Water Treatment Plant is one of MMWD’s three water treatment facilities. We’re in the midst of a series of phased upgrades to the plants that will extend the lifespan and improve the reliability of our water treatment operations. 
When you turn on your tap and clean water comes out, it’s not by accident. It takes a large and complex system to capture, store, treat and deliver water to your home or business 24/7/365. Though much of that water infrastructure is out of sight, it’s never out of mind for MMWD.

As the oldest municipal water district in California, we face significant challenges in maintaining our aging infrastructure. Parts of our water system date back more than 100 years. Many of our pipes, tanks and pump stations are reaching the end of their useful lives. Over the past 10 years, we’ve invested more than $200 million in capital projects to maintain our system. We expect to invest as least as much over the next 10 years to ensure a clean, reliable water supply for the future.

In short, when you pay your water bill, you are getting much more than just the water you use. You are also helping to take care of the complex system—from reservoirs to pipelines—needed to deliver that water to your tap. 

Did You Know?
  • Marin’s varied topography makes our water system unusually complex. To move water throughout our service area, we rely on 97 pump stations and 128 storage tanks—that’s an order of magnitude more infrastructure than many water agencies our size. 
  • MMWD maintains more than 900 miles of pipeline. Laid end to-end, our pipes would stretch from Marin into Canada! Almost half of our pipes are 50 years or older. 
  • With 18,500 acres of watershed land on Mt. Tam under our care, MMWD is the largest public land manager on the mountain. We’re fortunate to have a source of high-quality water in our backyard, but caring for our watershed lands has a cost. With support from our customers, we’re working to manage the impacts of invasive pest plants and climate change, and to reduce the risk of wildfire to our community.