You are invited!

Save Palo Alto’s Groundwater and the City of Palo Alto are pleased to announce that Prof. Kristina Hill, U. C. Berkeley, an expert on urban planning and mitigation for climate change, has agreed to share her knowledge and experience with us on April 24th from 7 to 8:30 pm at the Mitchell Park Community Center El Palo Alto Room. Please join us for her presentation on Planning for Rising Waters: Sea Level, Groundwater and Bay Edge. This event is free, but please register.

For years most coastal and Bay communities have focused their efforts on responding to sea level rise by planning and building sea walls, berms and other protective barriers against the water that will come ashore and threaten properties, shore ecosystems and infrastructure.   However, until recently, many communities have missed an important consequence of sea level rise – the concurrent rise of groundwater.

But, how important is groundwater rise? Modeling studies done for Hawaii and the state of New Hampshire indicate that groundwater rise can double the amount of area that would flood with only sea level rise. Additionally, this flooding could impact areas as far as 2.5 to 3 miles inland. This rise of groundwater can lead to increased risks of foundation instability, pipe infiltration and inflow, salinization of wells, premature road failure, remobilization of soil contaminants, flooding of  basements and underground garages and liquefaction. Levees and sea walls don’t address the problems cause by groundwater rise.

Our speaker, Dr. Hill, has intriguing ideas as to how cities can adapt to sea level and groundwater level rise in a seismic zone. Her lecture should be of interest to city planners, environmentalists, developers, policy makers, property owners, residents and everyone who wonders what we can do to mitigate and adapt to the rising waters now starting to be seen in the Bay Area. What we build today will likely last 30+ years.  We invite everyone to join the conversation and start thinking about how we can address the future now.

Dr. Hill Flier (printable, pdf)


  • The City of Palo Alto
  • Save Palo Alto’s Groundwater
  • The Sierra Club, Loma Prieta Chapter
  • Peninsula Interfaith Climate Action
  • Tuolumne River Trust
  • Palo Alto Neighborhoods (PAN)
  • Fergus Garber Young Architects
  • Palo Altans for Sensible Zoning



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Palo Alto’s 2018 Construction Dewatering Regulations Are Here!

The City of Palo Alto recently released its 2018 Construction Dewatering Regulations for those projects that will need construction dewatering.  The City also provides the following map so that anyone can see the City’s  current dewatering sites (as well as those from 2016 and 2017) by clicking on the image below:

You can also access Palo Alto’s dewatering map directly on the City’s website and on our maps page.

Continue reading

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Celebrating Groundwater Awareness Week, March 11-17

Life as we know it would be impossible without groundwater. It is the world’s most extracted natural resource and it supports our ecosystems.

Don’t take groundwater for granted. Pay it forward during National Groundwater Awareness Week, March 11-17, 2018, by letting others know the importance of groundwater and asking them to pass it along.

According to the National Groundwater Association the United States uses nearly 80 billion gallons of groundwater per day for public supply, private supply, irrigation, livestock, manufacturing, mining, thermal electric power, and other purposes. California alone pumps 10.7 billion gallons of groundwater each day.  About 45% of the United States population depends on groundwater for its drinking water supply.

The United States uses about  53.5 billion gallons of groundwater daily for agricultural irrigation, 67.2% of all the groundwater pumped each day.  In 1990 that number was 2.2 billion.

Groundwater is constantly threatened by overuse, misuse and contamination. We can be part of the solution by making small changes that cumulatively have a big impact:

  • Conserve water inside the home by taking short showers instead of baths and running full load of dishes and laundry.
  • Check for and repair leaky faucets and fixtures, indoors and outdoors.
  • Water outdoors only when necessary, and landscape with native plants that need less water.
  • Track your daily water use with the free 30by30 app to find where you can use less.
  • Always follow label instructions for household chemicals, and look for ways to decrease or cut fertilizer and pesticide usage.
  • Dispose of chemicals properly by taking them to recycling centers for household hazardous waste collection.
  • If you have a well on your property, have the well inspected by a licensed water well contractor once a year.
  • Teach others about ways to protect and preserve groundwater.
  • Advocate for groundwater!

Learn more about how you can get involved at

(Source:  The Groundwater Foundation)

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We Did It! But More to Do!

Based on the City’s data (below), with an average of 13.9 million gallons of groundwater pumped per residential basement, the City saved 42 million gallons of groundwater in 2017. This fresh yet non-potable water is almost 17 times the amount of emergency water stored in Palo Alto’s El Camino reservoir. Unfortunately, one hundred fifteen (115) million gallons of groundwater went down the storm drains so, clearly, there’s still work to be done.

Thank you to City Council for encouraging new ideas, to Public Works for exploring new options and doing all the heavy lifting, to the construction industry who shared their knowledge, skills and expertise, to the homeowners who chose to use cut-off walls for construction and especially to all of you for your support and advocacyIn case you missed it, the Palo Alto Weekly covered this topic in greater detail in a very informative article about dewatering/basement construction. Two of our members were quoted (nice job Keith and Dan!) and Dan’s illustrations of the broad area and local area dewatering methods were featured. So thank you also to the news media for covering this important issue. We would be remiss not to also thank the members of our own Advisory Board for their time and wise counsel and Palo Alto Matters, another highly regarded and highly recommended local publication, for its coverage of dewatering among other issues of concern to Palo Altans .

Now, for the work that lies ahead: the second reading of the 2018 Dewatering Ordinance took place Jan. 22nd.  We did not oppose the ordinance as written but think it does not go far enough in protecting our groundwater as it does not address dewatering for commercial construction nor dewatering near contaminated sites.    We would like to see some standards codified for commercial construction and dewatering near contaminated sites instead of these being decided on a case by case basis. These will help provide clarity and fairness for all stakeholders.

In addition to clear, effective regulations for commercial sites, we would like the city to adopt regulations for all projects that limit the amount and rate of water pumped.  These two are the key metrics that determine impacts on neighbors and relate directly to groundwater preservation. No one should be permitted to pump and dump arbitrary amounts of groundwater, period.

For years groundwater has been “out of sight, out of mind”. With Cape Town expected to run out of water in a few months and another looming drought in California we cannot afford to take groundwater for granted. As is already the case in Florida, due to a growing population and sea level rise, groundwater management will become ever more important for Palo Alto and other Bay Area cities. We hope the entire community continues to support our efforts to ensure that Palo Alto uses this natural resource wisely.

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2018 Dewatering regulations on the City Council Consent Calendar, Monday, Dec. 11, 7 pm

Proposed 2018 dewatering regulations for below ground construction are on City Council’s consent calendar for Monday, Dec. 11th, 7 pm, City Council Chambers, 250 Hamilton.  City Council accepts written and oral comments from the public on any item on the consent calendar.  It does not, however,  discuss items on the consent calendar.  It will therefore vote on, but not discuss, revisions to the dewatering ordinance this coming Monday.

In 2017 cut-off walls for three residential basements were successfully used with zero to minimal amounts of groundwater placed in the City’s storm drains.  While these work very well to reduce the waste of groundwater, Save Palo Alto’s Groundwater does not request that cut-off walls be mandated for all below ground construction that requires dewatering.  Cut-off walls have disadvantages, including use of potable water during construction, construction impacts, increased amount of soil unavailable for stormwater retention and possible interference of the cut-off walls with groundwater flows, these last two leading to increased risk of flooding.

Staff’s proposed 2018 dewatering regulations add the following requirements that address some impacts of construction dewatering to the current ordinance : a) Construction work must be continuous during the dewatering period, b) A pre-building survey and report on structures on adjacent parcels must be submitted, c) After an 8-week dewatering period trucking of water to irrigation sites increases from 1 to 5 days/week.

We have heard from various neighbors, builders and other stakeholders that the proposed Dewatering Ordinance needs improvement in several areas:

  • According to the Oct. 23, 2017 Public Meeting Groundwater Assessment Use slides, the estimate of the “safe yield” of groundwater for Palo Alto is 2,500 acre ft. /year.   This “safe yield” is the total amount of groundwater that may be pumped for any purpose per year, including groundwater for emergency situations, and should be incorporated in any Ordinance and Plan that allows groundwater pumping.
  • Require large commercial and residential sites to install cut-off walls to dramatically reduce required pumping. Specifically address the coming Marriot hotels on San Antonio Road that could conceivably pump up to 2,900 acre-feet of groundwater with broad area dewatering.
  • Require sites in or near contaminated ground water plumes to install cut-off walls (to reduce the spreading of the contaminant plume).
  • Improve the use of broad area dewatering by specifying “Best Practices” when designing pumping systems (such as a limit on flow rate of 60 gpm).
  • Include clear metrics and avoid case-by-case requirements and exemptions in the regulations.
  • Require data in the hydrogeology report that helps design a dewatering system with lower flow rates.
  • Address pumping and impacts to groundwater flows for railroad trenches and tunnels.
  • Consider the cumulative impact of all below ground construction and dewatering.

The following is an excerpt from Staff’s response to some of our concerns:  “In response to the issues raised by Save Palo Alto’s Groundwater, Staff believes that the appropriate course of action is to adopt the proposed Ordinance enhancements now, and consider the other suggested changes after the New Year. We concur that more work on this topic is needed, especially with respect to large commercial sites. But it is critical to get the proposed changes in place now for residential sites, to provide certainty for designers, and to avoid more “grandfathering “ of residential sites as has occurred in the past. Most of the new sites will be residential, not commercial, as in past years.”

We are requesting Council to a) approve the ordinance revisions on the consent calendar and b) as proposed by Staff, direct Staff to follow-up with additional amendments to the Dewatering Ordinance in Q1 2018.

Whether you are a homeowner whose property has been impacted by dewatering, an environmentalist who believes we should protect our groundwater, an emergency services volunteer who believes we’ll need groundwater for future droughts, a homeowner/builder who believes regulations are too onerous, etc. we invite you to attend the City Council meeting on Dec.11th at 7 pm and make your voice heard.

Thank you for your interest and your support.

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