News

Palo Alto firms up rules for pumping groundwater

Applicants will have to analyze impacts to nearby properties; propose 'avoidance measures' to minimize water waste

Responding to a rising tide of citizen concern, Palo Alto officials on Monday took aim at the controversial practice of "dewatering," and approved new rules for property owners who wish to pump groundwater so that they can build basements.

The practice of dewatering has become more visible and controversial over the past year as the number of basement projects has risen (there were 14 such projects in 2015, mostly in parts of Old Palo Alto that are above what is known as the city's "shallow aquifer") and as the statewide drought enters its fourth year.

The two concurrent trends have given rise to a new grassroots group, Save Palo Alto's Groundwater, which has been lobbying the City Council to curtail the practice of dewatering and to treat groundwater as a precious natural resource, rather than a byproduct of construction.

The grassroots group scored its first major victory Monday night when the council approved a set of actions aimed at educating residents about groundwater, accommodating residents who want to use the discharged water, and ensuring that new projects that require dewatering adequately consider impacts on surrounding properties.

The most significant new rule is a requirement that applicants submit a statement of effects of the groundwater pumping on nearby buildings, infrastructure, trees and landscaping. This requirement will take effect this spring, when groundwater pumping season begins (the practice is restricted between October and April).

Other changes include new requirements for fill stations, which are already required to be established as part of basement projects that require dewatering. The stations allow the non-potable groundwater that would otherwise go into the city's storm drains to be recaptured and used for other means, including construction cleanup and irrigation. These stations would now have to be able to offer sufficient water pressure to accommodate multiple users.

The council voted 7-2, with Councilwoman Karen Holman and Councilman Greg Schmid dissenting, to adopt the new rules, which council members acknowledged were only the first of a series of actions that they plan to take on this topic in the coming months.

Though everyone agreed that the new restrictions would be appropriate, both Holman and Schmid argued that the proposal doesn't go far enough. Schmid recommended specific policies about metering and proposed a 6-million-gallon threshold for groundwater pumping before contractors have to adopt mitigating measures (His colleagues decided against setting a specific limit). Holman argued that the proposals do not constitute adequate mitigations.

The actions were, in many ways, a compromise. Some members of the citizens group had lobbied the council to adopt a moratorium on groundwater pumping until the city has a better grasp of the issue and its environmental implications. Others questioned whether these restrictions are needed at all.

Local architect Dan Garber observed that the pump at the Oregon Expressway underpass discharges more water annually than all of the residential projects combined.

City staff acknowledged that the issue needs more analysis. To that effect, city officials are working with the Santa Clara County Water District to better understand the North County's groundwater systems, impacts of groundwater pumping and opportunities for recharging the groundwater. But most members agreed that the new regulations, which were vetted and unanimously approved by the council's Policy and Services Committee in December, are a promising start.

Phil Bobel, assistant director of Public Works, said the new requirement would require a contractor to identify the effects that the project would have on nearby properties and include "avoidance measures" to minimize the effects. Even if no impacts are identified, the applicant would need to implement measures that would minimize the rate and duration of pumping.

Before the vote, several members of the new citizens group urged the council to do its part to curtail what it sees as a massive waste of water. Rita Vrhel, a resident of Crescent Park, told the council that the topic "is not going away."

"We are faced with droughts and flooding in our future," Vrhel said. "The only choice is when this will be adequately addressed."

The group also submitted a detailed white paper on the topic that analyzed the level of water being pumped, considered the effects of the practice and criticized the city's prior studies on the topic, the most recent of which was commissioned about a decade ago.

"The nearly 300% increase in approved dewatering permits and over 100 million gallons of groundwater extracted during the 2015 do not appear to have been anticipated by the authors of the City's existing dewatering policies and regulations," the paper reads. "Current dewatering regulations do not accurately address localized impacts of dewatering, including, but not limited to: potential ground settling; reduced soil moisture for trees and vegetation; public compensation for the private use of community groundwater; potential impacts on public and private water supplies; and necessary changes in public policy in an era of climate change.

"Additionally, the longer-term and cumulative impacts of basements on aquifer flows and storm water drainage are ignored."

The council agreed to further explore in the coming months more dramatic ideas for curtailing dewatering, including charging property owners for the discharge of water; tailoring dewatering requirements to drought conditions; and making sure that numerous pumping projects do not happen concurrently in close proximity. Staff will return to the council later in the year with more analysis of these actions.

But the council majority generally lauded the additional rules, which City Manager James Keene characterized as an "intermediate step."

"You don't score a touchdown from (your own) 10-yard line," Keene said. "We're trying to move forward a little bit."

Vice Mayor Greg Scharff, who made the motion to support the staff recommendation, called the proposed changes a "measured and appropriate response."

"What this does is take this on as a pilot program and says, "Let's measure the groundwater, gain more data, and let's put some things in place to address some of the immediate concerns that the public has,'" Scharff said.

Councilman Tom DuBois called the action an "important step" and said the greater challenge will be figuring out how to put a price on a commodity that has traditionally been treated like construction waste. DuBois also joined several other council members, including Scharff and Liz Kniss, in thanking the citizens group for taking the lead on the issue.

"This is a great example of the public process and you've certainly gotten the attention of us and, I think, the entire community," Kniss said.

Comments

41 people like this
Posted by Geotechnical Engineer
a resident of Community Center
on Feb 2, 2016 at 9:40 am

[Portion removed.]

There is zero (0) geological or engineering background to support the City's move.

[Portion removed.]

The volume of waters removed during dewatering are insignificant.

The ACTIVE dewatering of City Hall withdraws more water than ALL of the temporary dewatering activities combined.

Look...if you just don't want to see new homes constructed with basements in your neighborhood just be honest and say so. If you dont like those pumps and settling tanks...just say so. Be HONEST...this is an anti-growth reaction without scientific basis.


64 people like this
Posted by Midtown
a resident of Midtown
on Feb 2, 2016 at 9:42 am

The quickest way to fix this is to count basement floor area in in total floor area. A basement is just a loophole in the total floor area calculations.


34 people like this
Posted by Paul
a resident of Downtown North
on Feb 2, 2016 at 10:18 am

Right, @midtown. What Palo Alto needs is more pointless rules, because we don't have enough of those.


58 people like this
Posted by Resident
a resident of Another Palo Alto neighborhood
on Feb 2, 2016 at 10:24 am

My own thoughts on this center around the logic that taking water out of the underground water plane will eventually cause subsidence and sink holes. Underground water takes space which dry ground will not fill. My high school volume experiments tell me that if you take the water out, gravity will cause whatever is above to resettle into the space.


38 people like this
Posted by My Take
a resident of South of Midtown
on Feb 2, 2016 at 10:29 am

Why does discussion of groundwater pumping no longer include the subject of underground toxic plumes and how the dewatering may have an impact on the movement of these, as well as the potential contaminants that might show up in the water being removed? Articles from the recent past such as, Web Link
Web Link would suggest that this is a factor.


20 people like this
Posted by Marc
a resident of Midtown
on Feb 2, 2016 at 10:51 am

@Geotechnical Engineer I agree with you. The problem is that all you have to do is present bad science and yell loud enough and the city and public rolls over.

@Resident. What you posted is an example of taking things out of context and is exactly what Keith is doing. Your "logic" isn't what happens in the dewatering. Water is not permanently taken out.

So far no one has been able to present solid proof that there is a problem. I would believe there is a problem
if you could show specific homes that have been damaged.

Take the map from the city that shows locations that have built basements and plot out all the homes that have been damaged and when the damage occurred. Show that there are clusters of damaged homes surrounding dewatering sites. Show the specific damage to the homes, get testimony from the home owners.

/marc


25 people like this
Posted by marjoon
a resident of Palo Verde
on Feb 2, 2016 at 11:01 am

marjoon is a registered user.

Just look at the trends, first Single Story Overlay, now this, don't you see similarities?

Geotechnical Engineer is SO RIGHT. "Look...if you just don't want to see new homes constructed with basements in your neighborhood just be honest and say so. If you dont like those pumps and settling tanks...just say so. "

If you don't like new houses, if you don't like two story houses, if you don't like the new residents, [portion removed] just say so.

I wish I had never moved to Palo Alto.


47 people like this
Posted by Emerson St Resident
a resident of Old Palo Alto
on Feb 2, 2016 at 11:17 am

The current housing code encourages new home builders to dig 1 and even 2 story basements, because basement square footage is not included in calculations of building coverage for determining property taxes.
This is a serious, unfair property tax loophole that should be amended.
Most new home construction sites in Old Palo Alto appear to involve digging basements, many of which require dewatering.


36 people like this
Posted by Green Gables
a resident of Duveneck/St. Francis
on Feb 2, 2016 at 11:17 am

Oh, come one, what we have now in Palo Alto are very large homes with very LARGE basements. Removing water below ground has a shifting affect on neighboring houses. Move to Atherton where you can have an acre of land for your gigantic house and gigantic basement.


34 people like this
Posted by Stan
a resident of Greenmeadow
on Feb 2, 2016 at 11:18 am

"Local architect Dan Garber observed that the pump at the Oregon Expressway underpass discharges more water annually than all of the residential projects combined."

Why aren't we fighting to stop the waste of water here. I figure it's low hanging fruit that people can go after.


36 people like this
Posted by stretch
a resident of another community
on Feb 2, 2016 at 11:20 am

There IS a problem when people are doing their best to cut back on water use in a drought and they have to watch thousands of gallons of water going down the storm drain with no effort to save any. It's just not something one wants to see when trees and plants are dying due to lack of water.

Ban the basement!


36 people like this
Posted by Roy
a resident of Leland Manor/Garland Drive
on Feb 2, 2016 at 11:38 am

@Geotechnical engineer You wrote "The volume of waters removed during dewatering are insignificant." Insignificant for some purposes, perhaps, but not for others. Specifically, trees in the immediate vicinity of the dewatered area, especially those already stressed by drought, can be negatively affected, according to the arborists and landscape experts I have consulted. If you are an expert on such matters and have a differing view, please provide the factual basis.

I'm all in favor of rule-making based on facts. I'm also in favor of fact-based discussion, rather than name-calling. You evidently disagree with the proponents of this regulation. That's fine, but it doesn't make them Luddites, and characterizing their actions as "BEYOND STUPID!" (emphasis: yours) doesn't get us any closer to the facts.


31 people like this
Posted by Why Not
a resident of Another Palo Alto neighborhood
on Feb 2, 2016 at 11:39 am

Tax the basement!


28 people like this
Posted by Save Palo Alto's Groundwater
a resident of Leland Manor/Garland Drive
on Feb 2, 2016 at 11:47 am

To @Geotechnical Engineer “Be HONEST...this is an anti-growth reaction without scientific basis.”
From California’s Water Action Plan (2016) Web Link : “Historically, inconsistent and inadequate tools, resources and authorities have made managing groundwater difficult in California and have impeded our ability to address problems such as overdraft, seawater intrusion, land subsidence, and water quality degradation. Pumping more than is recharged lowers groundwater levels – which makes extracting water more expensive and energy intensive. Under certain conditions, excessive groundwater pumping could mobilize toxins that impair water quality and cause irreversible land subsidence which damages infrastructure and diminishes the capacity of aquifers to store water for the future.”

From the Union of Concerned Scientists: Web Link
“California is increasingly turning to groundwater to meet its water needs. To ensure enough water for generations to come, the focus must shift to make groundwater supplies more reliable and sustainable.”
How is trying to make sure there’s enough water for all anti-development? If anything, it’s pro-development. With more people, we will need more water.

to@marjoon “If you don't like new houses, if you don't like two story houses, if you don't like the new residents, specially those whose skin color is different, just say so.”

Please!!! I’m brown skinned. Let’s not bring racial overtones to this. I think we can all agree that we all need water, now and in the future.


37 people like this
Posted by Curmudgeon
a resident of Downtown North
on Feb 2, 2016 at 12:04 pm

"There is zero (0) geological or engineering background to support the City's move."

There is a much more compelling background. Ground water is a public resource. It needs to regulated for the public benefit.

The city should charge pumpers the market per ccf rate.


6 people like this
Posted by Joe
a resident of Another Palo Alto neighborhood
on Feb 2, 2016 at 12:04 pm

Carlsbad Desalination Project:
Web Link

Let’s hope that all of the links provided by “experts” on California’s water use update their literature to include desalination as a source of water for Californians.


52 people like this
Posted by Sylvia
a resident of Midtown
on Feb 2, 2016 at 12:22 pm

@Geotechnical Engineer. No effects of groundwater pumping? How about this: 34 years in the same house. 33 years of the doors to my house and garage working perfectly. Two or three houses on my street are built with basements. And 3 of my doors don't work properly. The dead bolt for my kitchen door stuck locked, obviously because the door itself shifted down. The door to the Living Room was very difficult to open, causing a lot of key jiggling to get inside. My garage door (not the one the car goes in - the other one) would not close no matter how hard it was slammed.

My son spent a day repairing these things, replacing locks and adjusting the garage door so could close it. I am grateful to have a handy son and the cost to me was only new locks. But, if I didn't have a handy son, I would have had a much greater expense.

This is so someone can skate on the FAR to get the most out of the lot they purchased.


30 people like this
Posted by Honest
a resident of Midtown
on Feb 2, 2016 at 12:26 pm

Just to clairify a point.
Basements are not counted in the floor area as calculated by the Zoning Code.
They ARE used in the calculation of school impact fees and in the determination of the property tax ( under value of improvements )... So in fact, they are taxed.

Be honest with yourself.. It's ok not to like basements .. For whatever reason.. Just don't try to disguise it in the name of some social justice.


18 people like this
Posted by GW Guru
a resident of Another Palo Alto neighborhood
on Feb 2, 2016 at 12:31 pm

@Save Palo Alto's Groundwater please realize that you are taking different problems with groundwater pumping from different areas of the State, and confusing them as one issue. No one is depleting an aquifer here. @Geotechnical Engineer is right on the money. The Grassroot's Group has been told their science is bad, and misplaced, but they don't care to hear that. Dewatering is not impacting our local groundwater regime. It is like removing a grain of sand on the beach. You might not like that local water companies charge you for, and ration, your water use because they procure, treat and deliver safe water to you while this groundwater gets discharged in front of you, but that is not a pertinent part of the issue. Does dewatering waste or cause impacts? The answer is almost always no. Dewatering can cause some very localized settlement, but that is always checked by engineers. This issue is being driven by too many people who don't understand the science (or quote high school science).


20 people like this
Posted by resident
a resident of Old Palo Alto
on Feb 2, 2016 at 12:52 pm

Shouldn't basement square footage be considered in a building's lot coverage footprint (not as "improvement") in determining property taxes on liveable space?


27 people like this
Posted by My Take
a resident of South of Midtown
on Feb 2, 2016 at 1:00 pm

On the subject of the toxic plumes, here are some questions I consider relevant:

Where has this issue gone? Not long ago it was claimed that groundwater removal for building sites in the midtown area was causing toxic plumes to move toward the sites, with the possible result of exposing residential properties to toxic vapors. Has the financial benefit of making basements caused the removal of this subject from consideration, or have these chemicals disappeared from beneath Palo Alto?

If water removed from these sites is made available for people to use, are they to be informed of any chemicals that might be in them? Will it be safe for watering fruit trees, vegetable gardens?

Although I don't know enough about the geology and engineering factors involved to form a useful opinion, I should note here that during the recent drought, although there are no basements being dug anywhere near my home, we too have experienced unusual shifting of our structure, along with the accompanying sticking doors, cracks, gaps, and so forth.






27 people like this
Posted by Cid Young
a resident of another community
on Feb 2, 2016 at 1:04 pm

I agree with Stan and Stretch. Water waste is an issue. Why not require the extracted grouund water to be recycled? That seems like a win-win. Even if sent for pre-treatment to purify it, there are uses for that water, including carwashes, dust mitigation and ornamental landscaping irrigation that does not require potable water.

I also agree with WHY NOT that the assessor should start to tax the basements. As a REALTOR®, I have seen homes built in Atherton with lavish amenities such as below ground level home theaters, business entertainment complexes including expansive wine cellars and coporate dining areas. Normally garages and other unimproved areas are not treated as "living areas" but some of the uses now being located in "basements" are not simple storage units, like basements of yesteryear, and do add intrinsic value to the properties.


18 people like this
Posted by Crescent Park Dad
a resident of Crescent Park
on Feb 2, 2016 at 1:28 pm

It is pretty common (in the USA) not to include basement sqft. when calculating a home's total square footage.

*It is not a property tax loophole however.*

There are two factors that determine our variable property taxes (aside from parcel taxes, bonds, etc.):
1. Value of the land (based on location and acreage/sqft)
2. Value of the improvements on the land (based on building costs)

Everyone knows that Palo Alto land is incredibly expensive. Look at your latest Santa Clara County property tax bill and you'll see it for yourselves. I think we can all agree that the assessed value of the land is far greater than assessed value of your "improvements".

The assessed value of improvements on the property is driven by the costs to build the existing structure on the property - those costs include foundations and basements. The county gets those numbers from building permits filed with the city. These calculations are applied on existing, new and remodeled homes.

For example, if an owner of a 100 year old house decides to jack-up the house and build a basement, the costs of that improvement are assessed & added onto the existing improvement property tax figure...even though the new basement is not calculated as livable square footage for zoning purposes. Even under Prop. 13, the improvement costs are assessed at today's building permit values.

Taking the above example further. Say the 100 year old house was purchased in 1984 (post Prop 13) for $200K. That $200K has been assessed under Prop. 13 rules all the way to the present year. I'm guessing roughly $500K now (at least for our example, OK? Don't shoot me if I'm wrong - just trying to show how basements are added onto prop tax). But if the owners jack-up the house and add a full-basement (let's say the permit costs are $400K), then the $400K is added to the assessed value of the improvements. So the new assessed improvement value would be $500+400=$900K.

Of course, if someone chooses to scrape and build a new house and basement - the entire project cost (as calculated on the Palo Alto building permit) is used as the basis for calculated the assessed value of the "improvements" on the property. The county does not exempt basement building costs.

Let's say a property is purchased for $2.2mil. The county would reassess the property and issue an amended property tax bill. Most likely the increase would be applied to the land value and not to the existing structure/improvement. Say the new property tax $2mil for land and $200K for improvements. The new homeowners decide to scrape the old house and build new - including a full basement. Total expected building costs (per Palo Alto building permit) comes to $1.5mil. The new assessed property tax would now be $2mil land and $1.5mil improvements = $3.5mil. Again, this includes the basement in those calculations.

BTW - same goes for attic space. Attic space (typically less than 5ft overhead space) is not counted in square footage of a home. But the costs to build the attic are included in calculating the overall land improvement costs.


Questions?


36 people like this
Posted by Biased architect
a resident of Old Palo Alto
on Feb 2, 2016 at 2:04 pm

Daniel Garber doesn't see a problem because he designs houses that pump water. The house on the corner of Cowper and Seale during construction pumped water out for weeks and weeks and weeks.
Garber's name was proudly shown on the sign in front of the ongoing construction.


8 people like this
Posted by Chris C.
a resident of Community Center
on Feb 2, 2016 at 2:52 pm

Just to clarify a couple of points:

a) the purpose of property tax is to raise funds for the government. The rate charged is proportional to the value of the property. So if your house-with-a-basement is worth more than the equivalent house-with-no-basement, you pay more tax. As I understand it, there is no per-square-foot assessment metric used, and basements are *not* ignored when performing an assessment.

b) the square-footage limitation on home construction is intended to limit the visual size of houses. Basically, Palo Alto has decided that if you own a house, there should be a limit to how huge of a structure you should have to see next door to you. As a neighbour, you can't see a basement -- hence it is not included in the calculation.


18 people like this
Posted by Jim
a resident of Downtown North
on Feb 2, 2016 at 3:58 pm

What does charging for extraction do? It favors the rich who care little about costs. It discriminates again middle income citiZens who cannot afford to live here now. So the rich get richer and the poor get poorer. It leaves the common good out of the equation. Just say no to more basements at or below the water-table.


22 people like this
Posted by Jim
a resident of Downtown North
on Feb 2, 2016 at 4:02 pm

Just say no basements below the level of ground-watgere. That serves the common good.


24 people like this
Posted by mcm
a resident of Community Center
on Feb 2, 2016 at 4:56 pm

I am strongly opposed to the building of these basements. I think there should be a halt to planned basements to be built until all the facts have been studied. I think the city council owes that to residents of the city.


10 people like this
Posted by Plane Speaker
a resident of Crescent Park
on Feb 2, 2016 at 5:10 pm

As usual fiction and innuendo have saturated the City before the truth has even woken up.

The best we can do is base this on facts, but those facts are going to come months after all
of these ridiculous claims are being shouted and repeated.

This is just pathetic. People should have the right to build a basement, if there is too much
groundwater they need a way to temporarily get rid of it while building the foundation.

The notion that trees are dying, houses are shifting or we are going to get earthquakes or
use up our groundwater is silly on the face of it.

The only reason I can see that this would really impact other people in the constant
vibration and noise of the pumps, and if that is too loud or annoying another method
or compensation to those impacted should be made.


7 people like this
Posted by Commentator
a resident of Professorville
on Feb 2, 2016 at 5:29 pm

"People should have the right to build a basement, if there is too much
groundwater they need a way to temporarily get rid of it while building the foundation."

Nobody is denying a basement. Only the flagrant wastage of a public resource.

Engineers have been building structures in bodies of water for centuries. A well-proven technique involves building a temporary cofferdam to keep the water out of the work area. Surely anybody who can afford to buy a multimillion $$ property, tear it down, and build a palace with a hole under it can afford an added few $100k to do the job right. If that breaks their bank they are too penurious to be playing in the Palo Alto demo derby. It's that stark simple.


9 people like this
Posted by Marc
a resident of Midtown
on Feb 2, 2016 at 7:04 pm

@Commentator. Here we have another example of taking things out of context.

Yes, people build cofferdams to hold back water and soil during construction. The most common method involves a pile driver and retaining plates. If the residents think basements are bad now, just wait until they have a piledriver next to their house. Then see how much damage to adjoining buildings there are.

An alternative used in some instances is freezing. Generally used where there is no other cost effective method and the soil is too fluid for a cofferdam.

So the generally accepted practice here is to dig a hole, install pumps and drain. Cost effective and minimal impact on the neighbors and environment.

/marc


46 people like this
Posted by Wassup
a resident of Another Palo Alto neighborhood
on Feb 2, 2016 at 7:19 pm

How can basement dewatering be an insignificant amount of wAter loss when some properties drain aquifers for TWO YEARS or more. A prime example is Larry Page's house, which took nearly four years to build. The first draining lasted six months. The second draining lasted a sold two years, The drainage pipe went from the back of the property down Bryant to Cal Ave. The pipes were ther So LONG that they were nearly flattened in places where people had driven over them in order to go into driveways.


12 people like this
Posted by ConfusedMessage
a resident of Community Center
on Feb 2, 2016 at 8:00 pm

It is abundantly clear that many in the 'groundwater' crowd simply don't want basements, and have little interest in groundwater, or the science behind it.

Rather, it is a convenient and visible cudgel to beat up builders during a drought.

They found a hammer, and intend to beat any basement builders.

Read the comments above - some want to tax, others want to ban basements REGARDLESS if groundwater is disturbed or not.

It is disingenuous to conflate groundwater with basements.

Why not simply tell city council: 'I don't like rich people having a basement, so I am going to conflate this with water waste in a drought'

Nice


38 people like this
Posted by Cheryl Lilienstein
a resident of Barron Park
on Feb 2, 2016 at 9:22 pm

Basements are not a problem. Wasting water is.
It's a bad argument to say that we should not care about draining the aquifers under neighborhoods because lots of water is drained from, say, the Page Mill Underpass or City Hall. Following this logic, why bother conserving water at all?

Further: Draining water from the Page Mill underpass is a matter of public safety.
Dewatering basements, on the other hand, is a private act that depletes a public resource.

The aquifers have been part of the understory for eons, yet have not been adequately mapped. Why insist that the effect is inconsequential, when you can't know?
And there are plenty of examples of subsidence around fracked areas, are there not? Why not take a lesson?

Perhaps an enterprising entrepreneur could develop a device called The Public Cumulometer that measures all the "no significant impacts" that accumulate significantly. Crowdsourced, of course.


11 people like this
Posted by Commentator
a resident of Professorville
on Feb 2, 2016 at 10:17 pm

"If the residents think basements are bad now, just wait until they have a piledriver next to their house."

There are other methods. Do your homework.

To take the Libertarian view: Let them do what they want with the water under their property, but leave the neighbors' water under the neighbors' property. Larceny is not only unneighborly, it is illegal in most states.


9 people like this
Posted by ConfusedMessage
a resident of Community Center
on Feb 2, 2016 at 10:33 pm

@Cheryl writes :"The aquifers have been part of the understory for eons, yet have not been adequately mapped. Why insist that the effect is inconsequential, when you can't know?
And there are plenty of examples of subsidence around fracked areas, are there not? "


Yeah. Right....Except they have been mapped, and subsidence studied. Which won't happen until pumping down to about 160'

Which basement dewatering will never do.


All old news. All in studied reports. All hashed over a dozen times in these forums.

The dewatering (debasementing) crowd either doesn't want the facts, or conveniently ignores them. After all, this isn't about facts or water.

It's just about basements.


35 people like this
Posted by Curmudgeon
a resident of Downtown North
on Feb 2, 2016 at 10:41 pm

"It's just about basements."

Naw. I got a basement. No dewatering needed, then or now. Dry as the Kalahari.

It's all about building in the right place. Digging a basement into the water table is just silly.


22 people like this
Posted by SteveU
a resident of Barron Park
on Feb 3, 2016 at 7:14 am

SteveU is a registered user.

People keep mentioning Oregon Expy underpass.
How much (%) of the pumping is:
Irrigation (nearby, over watering?) Seepage Runoff ?
Street Surface (Rain) Water drainage?
Some locations are not suitable for all forms of construction.
Just because we have the ability to overpower Mother Nature with pumps and sealant, does not always make it a good idea.

Why not simply use a rule of thumb.
In Summer, (not in a rainy season)
Drill a Test hole, basement depth+n feet deep, if it would make a good, class x water well, then no basement allowed .
n being a buffer depth and x being a GPH threshold, to be set by engineers.




12 people like this
Posted by Geotechnical Engineer
a resident of Community Center
on Feb 3, 2016 at 8:15 am

Just to be clear.

More than 10 years ago CPA adjusted the rules for basements and waterproofing. These rules were dead on and common sense. The rules were set after review with engineers and hydrologists. The rules were based on sound engineering principals and associated good public policy.

The pumping that is being discussed is TEMPORARY dewatering to permit safe construction of the basement and foundation.

Once the foundation/basement is constructed, the current policy permits NO dewatering. Period.

Construction dewatering is a TEMPORARY very local situation with no demonstrable ill effects.

It is VERY expensive to dewater. The project owner has a HUGE economic incentive to complete the temporary work as soon as possible. There is no plausible reason to add more incentive to remove as little water as possible.

The fact that neighbours are postulating ridiculous effects of localized dewatering, betrays the fact that they are making this stuff up.

Again, if you don't want to see a big house replace a small house. Be HONEST and admit that this is the problem and adjust zoning/planing accordingly. You don't need to make stuff up just to stop that big house from being constructed.

Long term Palo Altans have always had an issue with a 1,200 sf 2 bedroom home with two car garage being replaced with a 6 bedroom home with a one car garage. The basement is not the problem as you never see it...its that huge home looming over your fence.

If you don't like small homes being replaced with big ones...just be HONEST and say so. You don't need to fabricate an issue.


32 people like this
Posted by PA Resident
a resident of Old Palo Alto
on Feb 3, 2016 at 9:37 am

While the house next to our 1920's home was being built with a basement that required ground water pumping, all of our doors and gates needed realignment several times during the construction and for months afterwards. We experienced minor cracks in some walls. Our lot is only 50' wide and the new house next door occupies much of its property's width. Also the downspouts of the neighbor's home simply direct the rainwater a few feet away from its base-and directly toward our house. Guess where the water goes? The lowest porous point: our 1920's basement! There is no area around the neighbor's house for water to soak into the ground as the buildings occupy so much of the land. The water has to go somewhere. Maybe storage tanks underground for use during the dry months? We have lived here for 30 years and none of these problems existed prior to the construction of the house with the basement.


20 people like this
Posted by what I dont get
a resident of Another Palo Alto neighborhood
on Feb 3, 2016 at 10:25 am

what I dont get is why the city allows basements in flood zones.


10 people like this
Posted by Crescent Park Dad
a resident of Crescent Park
on Feb 3, 2016 at 11:54 am

The city doesn't allow construction of basements in flood zones.

Pumping groundwater does not equal flood zone status.

You can check a property's flood zone designation via the Palo Alto city website.


8 people like this
Posted by My Take
a resident of South of Midtown
on Feb 3, 2016 at 12:09 pm

If the ground water is polluted, then it is not a resource that may be wasted. Rather, it has already been wasted.

Of course, by pumping it, if you are causing underground chemicals to migrate, endangering people, then you need to stop pumping it.

If you choose to ignore the subject because if it is real, then neither of the two sides above wins the argument. What can be seen in the responses after I brought it up is that neither side is interested in reality - only in winning. The money people keep going on about money. The resources people go on about water waste. It's too bad for Palo Alto that the most vociferous and energetic people are so often the ones with closed minds.


29 people like this
Posted by Another Old Palo Resident
a resident of Old Palo Alto
on Feb 3, 2016 at 2:50 pm

A construction project which pumped out water to dry out their site, took the moisture away from the foundation footings under our home. We believe this caused significant damage to our home, and we recently had costly remodeling done less than 10 years ago. The pumping from that construction site removed moisture in the soil which supported our circa 1930 home. We had cut back on landscape watering like our neighbors, so the water could not be replaced as fast as it was being withdrawn on a property fairly far away. The damage is done now.
We are mad and we are moving.
And what about damage to under grounding piping?
Didn't a water main break a few years ago near California Ave and Bryant?
It was a huge loss of fresh water - millions and millions of gallons.
It occurred in an area where a substantial amount of groundwater pumping had been pumped out. There is no way to prove this, but all these things can't possibly be anecdotal.


Posted by ConspiraciesAboutWater
a resident of Old Palo Alto

on Feb 3, 2016 at 3:05 pm


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1 person likes this
Posted by Eileen Wright
a resident of Crescent Park
on Feb 3, 2016 at 3:57 pm

"The city doesn't allow construction of basements in flood zones."

Here is yet another nanny state encroachment on our freedom. What's the big deal? I buy flood insurance. I pay my premiums.



25 people like this
Posted by Curmudgeon
a resident of Downtown North
on Feb 3, 2016 at 4:13 pm

"Pumping groundwater does not equal flood zone status."

Strange, because having to pump groundwater means you are in a zone of permanent subsurface flood. Digging a basement into a permanent flood is just silly.


25 people like this
Posted by Curmudgeon
a resident of Downtown North
on Feb 3, 2016 at 4:24 pm

"Once the foundation/basement is constructed, the current policy permits NO dewatering. Period."

No OVERT dewatering, that is. But you can bet your bippy there is a lot of COVERT leakage dewatering into the sanitary sewer system, the result of buckling caused by the huge hydraulic stress on the basement walls and especially floor. The costs of this additional load on the water treatment system are passed onto all of us ratepayers. It's flat out oligarch socialism: the public underwrites the privileges of the few.


2 people like this
Posted by Another Old PA Resident 2
a resident of Old Palo Alto
on Feb 4, 2016 at 9:00 am

Dear Old PA Resident,

Agree. What are you going to do with your house? Maybe we will hold our house as rental property while it experiences the long term consequences. What a great way to create a slum in Old PA!


4 people like this
Posted by Crescent Park Dad
a resident of Crescent Park
on Feb 4, 2016 at 11:19 am

"Here is yet another nanny state encroachment on our freedom. What's the big deal? I buy flood insurance. I pay my premiums."

Believe me, I'd like it that way myself, so don't shoot the messenger. But the policy is in place as part of a deal Palo Alto made with FEMA when the flood zones were expanded back in the mid-90's. The entire city is afforded "low" flood insurance premiums in exchange for the prohibition of basement construction in residential areas.

And don't forget there are other flood zone restrictions when it comes to residential construction. Especially when it comes to remodels/additions. Do your homework before spending tons of cash on architects, engineers and plans.


14 people like this
Posted by Be Positive
a resident of Leland Manor/Garland Drive
on Feb 4, 2016 at 1:06 pm

Be Positive is a registered user.

It used to be that if your basement was above the water table, you could build, if it was below the water table, you could not. Why not go back to those simple rules? You can build a basement if you don't need to dewater.


2 people like this
Posted by Crescent Park Dad
a resident of Crescent Park
on Feb 5, 2016 at 12:28 pm

When was that?

You are aware the water table fluctuates both in depth and in route? Perhaps that's why it is no longer a factor. Plus today's building technology allows construction of water-tight basements and garages.


7 people like this
Posted by Fear Groundwater
a resident of Old Palo Alto
on Feb 5, 2016 at 5:58 pm

"...today's building technology allows construction of water-tight basements and garages."

Construction, granted. Permanent water tight, less certain. The water subjects the walls and floor to tremendous unrelenting buoyancy stress.

For example, just two feet of water head above the floor-earth interface exerts 1 psi upward pressure over the entire basement floor. That's 144 lb/sq ft = 216,000 total pounds (108 tons) of static buoyancy lift over a 1,500 sq ft footprint. You need a 10-inch thickness of concrete floor to nullify that lift on a per area basis. Less than that subjects the floor to a continuous bulging moment about the foundation piers which will ultimately crack the floor. Double those numbers with a 4 ft head, and double them again for 8 ft. That house better be righteous heavy, with a very, very thick basement floor.

"You are aware the water table fluctuates both in depth and in route?"

And with rainfall, causing a varying buoyancy load. Very bad, that.


3 people like this
Posted by Save Palo Alto's Groundwater
a resident of Old Palo Alto
on Dec 15, 2016 at 7:25 pm

Thank you to all who wrote letters, showed up and spoke up for reducing groundwater waste for construction purposes at the Policy and Services Committee on Dec.14th. Thanks to your support and advocacy, together we changed the game!
It’s clear that the Policy and Services Committee and City Staff now understand that wasting water is the issue, and that it’s not acceptable politically. Or morally. Or for any city that thinks of itself as sustainable. They also know that alternative construction methods are available and practical.
See our blog Web Link for more.
One of the highlights of the many presentations to the Policy and Services Committee was the 2-minute animated video made by Cate A, an 8-year old in 3rd grade. The message is powerful – please share with your friends.
Web Link


3 people like this
Posted by ACR
a resident of Old Palo Alto
on Dec 17, 2016 at 10:08 am

I hope the optimists are correct. If the uncomfortable, barely audible meeting in the cityhall lobby is an indication of the city's intentions, they may scuttle any change that interferes with developer profits. We shall see.

Architect Dan Garber had a chance to do his number, and development advocates Kniss and even Drekmeier praised him. My neighborhood watched the Garber designed structure on the corner of Cowper (at Seale) emptying water out for weeks and weeks and weeks.

More people would have spoken at the meeting if the dreadful ambience and broken sound system worked. The expensive Anti-Community "Room" is a big fail.


1 person likes this
Posted by Save Palo Alto's Groundwater
a resident of Old Palo Alto
on Dec 17, 2016 at 7:47 pm

There's no doubt that Dan Garber has designed houses that were built with basements that resulted in (huge) amounts of dewatering. But, we are convinced that he's sincere in his desire and intention to change going forward, now that he understands the issues. If his clients permit, he will likely use these "advanced methods," i.e. cutoff walls for 1 - 2 projects this year.

We're optimistic, but the proof is in the pudding.


3 people like this
Posted by ACR
a resident of Old Palo Alto
on Dec 18, 2016 at 4:27 pm

[Post removed.]


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