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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Fracking in Santa Clara County

Did you know fracking for oil and gas production is permitted in Santa Clara County?

The Sierra Club invites us to write to the Santa Clara County Board of Supervisors, BoardOperations@cob.sscgov.org, requesting a ban on fracking in Santa Clara County. Although there are 15 gas producing wells in Santa Clara County, there is no fracking yet.  However, the potential for fracking exists and neighboring counties of Monterey, San Benito and Santa Cruz and the city of Los Angeles have already banned fracking.

In addition to the potential contamination of ground and surface water, Wikipedia lists methane emissions, air pollution, migration of gases and hydraulic fracturing chemicals and radionuclides to the surface, the potential mishandling of solid wastedrill cuttings, increased seismicity and associated effects on human and ecosystem health as other possible impacts from fracking.  After reading this powerful article it is clear that we cannot risk contaminating our groundwater, impacting peoples’ health and becoming another Washington County, Pennsylvania.

Please join us and the Sierra Club in asking the Santa Clara Board of Supervisors to ban fracking in Santa Clara County.  You might also write to the Santa Clara Valley Water District, the groundwater steward for the Santa Clara Water Basin.  Most effective may be to email the director for your district (e.g. gkremen@valleywater.org and copy the full board for the record, board@valleywater.org.

This Thanksgiving we give thanks for your interest and support in protecting our groundwater.

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Where’s the protection for residents’ homes?

This evening, Oct. 23rd at City Hall, 250 Hamilton Ave., City Council will discuss and likely certify the Final Environmental Impact Report (FEIR) for our City’s Comprehensive Plan. This topic is scheduled for 7:45 pm but may start earlier or later depending on length of discussion of earlier topics.

The FEIR is a very lengthy document that covers many important topics such as housing, noise, transportation, etc. If any of those topics are very important to you, we encourage you to read and comment on the relevant sections of the FEIR.

We took a quick peek at the Hydrology section (FEIR Vol. 1, page 3-14, Adobe page 76) and while protection for groundwater is included, we are dismayed at the following paragraph.  Note: Cross-outs mean that the original language is dropped. 

“Mitigation Measure HYD-2: To reduce potential impacts associated with construction dewatering the proposed [Comprehensive] Plan shall include policies that address achieve the following topics:

  • Impacts Avoidance of the impacts of basement construction for single-family homes on adjacent properties, public resources, and the natural environment and safety.”

Notice that avoidance of dewatering impacts on “adjacent properties and public resources” is eliminated!

Yes, we want groundwater to be considered a resource and the FEIR addresses that. But last week we visited a homeowner whose property only three months ago was fine and now has extensive, and probably expensive, damage (see photo below). He is researching his options so we are withholding his name and address.

Public infrastructure and basement owners, old and new, are not immune from damage either. People with old utility basements and newer basement construction alike tell us of replacing basement drywall and insulation during or shortly after nearby dewatering due to water damage.  Some owners just repair and sell.  This is a matter of public record since City permits are required for this work.  It is important to note that not everyone near a dewatering site will be impacted.  There are many factors involved including types of soils, location (on an old stream bed?), construction type, etc.

We know your time is valuable and we will be asking you to attend the City Council meeting on dewatering that will probably be scheduled in November. However, if protection of all private and public property from dewatering impacts is important to you please attend this evening’s City Council meeting or write to City Council at city.council@cityofpaloalto.org and let them know.

We all expect increased inconveniences from nearby construction:  noise, traffic, parking, etc.  Homeowners shouldn’t be expected to pay thousands, and in some cases, tens of thousands of dollars for impacts from dewatering.  Even if your house is not impacted, we all pay for damaged infrastructure including broken water mains, sewers lines, etc.

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Promising Solution or Potential Problem?

As we near the end of Palo Alto’s dewatering season, October 31st, we face a dilemma. Do we support the use of cut-off walls for underground construction where the water table is high or not?  We’d like you suggestions and comments.  Save Palo Alto’s Groundwater is hosting a table at this Sunday’s, October 1st, Midtown Ice Cream Social, Hoover Park, 1 – 4 pm. Either in the comments section below or at the Ice Cream Social we would like to know what you would like the City to do about construction dewatering.

The City’s Public Works Department released the chart below that shows the results of three finished 2017 City of Palo Alto dewatering projects. Item number 3 shows a project that used cut-off walls. Not only did this project pump out less than 2% of the amount  of groundwater pumped by the other projects that used conventional dewatering methods, it was able to percolate back all this groundwater so that this process didn’t waste any groundwater! This project also had less impact on neighboring properties, the canopy and infrastructure because of the smaller groundwater drawdown.

Terrific, isn’t it? What’s not to like? One of our concerns about all underground construction is its impact on flooding. Underground construction means the removal of soil – soil that we depend on to retain and slowly release storm water on its way to the Bay. Not only is the removed soil unavailable for storm water management but, also, all those underground basements and garages can act like sticks in a stream. If beavers could speak they would tell us that with a few sticks we can build a dam – a dam to the underground flow of storm water during heavy rains.  With the loss of this soil and underground construction acting as dams, the City will have to build ever more expensive  infrastructure to handle heavy rains and reduce flooding.

But if we are building basements and underground garages already anyway, what’s wrong with using cut-off walls?  To be effective, cut-off walls need to be built down to a non-water bearing layer (clay layer).  In our area this depth is roughly twice the basement’s depth. This means we essentially double the amount of soil unavailable to absorb storm water and block water flow through much of the lot   Do we understand the impacts of basements or cutoff walls on flood risks?  We think not.

Thank you for your interest and your support.

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