Water table

Have you ever wondered about the depth of the water table, or if the Belwood, Belgatos, Surmont and nearby neighborhoods have a high water table?

Today I checked the website of the Santa Clara Valley Water District, also known as Valley Water, for info on our water table’s depth. Our water table is more shallow than I expected, just 10 – 20 feet in our far east corner of Los Gatos!

I marked up a screenshot and linked the map to the source, so if you click on it you will find our neighborhood water depth info on the Valley Water site.

 

Map of groundwater depth in Belwood Belgatos Surmont and nearby water table 700x523 - Water table

Click to visit the Valley Water site for groundwater depth

Ours is not the highest water table area or the smallest depth to first groundwater. The Edelen District, near Old Town Los Gatos, appears to have a depth of just 5-10′. It’s close to the Los Gatos Creek, so I imagine that may have something to do with it as well as seepage from the Santa Cruz Mountains.

Unsurprisingly, when I checked areas adjacent to the San Francisco Bay, the depth to first groundwater was between 0 and 5 feet.

What is a high water table? Does the Belwood area have a high water table?

Per Cotterill Civil Engineers:

A high water table area is defined as any area where the water table is within 1.8 metres, or 6 feet off the ground surface during the frost period up until the end of August or within 2.4 metres or 8 feet of the ground surface during the rest of the year.

It looks like the answer is no, we don’t have a high water table here generally. The depth to groundwater can change with heavy rains or with drought, so it is possible that at times water could percolate up in some circumstance. Since this is the average range for our area, any particular home or parcel may have something unique and different. You’d need to do some sort of testing to find out the actual depth to first groundwater for any specific address.

Other water issues

Many homes in this area do have water issues as there’s runoff from the hills, and sump pumps are commonly found in homes in our neighborhood. Water can travel downhill both above and below the surface, my drainage experts tell me. Not every property has the same level of challenges with managing surface or subsurface water. Foundation problems, which often are related to water issues, are not super uncommon, either, but most can be prevented by managing the flow of water away from the house, particularly from the downspouts. That’s low cost prevention but of the homes I see, probably only 10% have the water directed away from the home. Big mistake!

Curious about the groundwater depth beyond Santa Clara County? I found a list of the groundwater depth in various cities or towns in California which shows most of Los Gatos as having at least 10′.  Parts of Foster City and Redwood Shores (Redwood City) have less than 5′.

 

Related Reading

Where are the natural hazards in Los Gatos? (on the Live in Los Gatos Blog)

Interactive map to view risk of flooding from dam failure in Los Gatos (Live in Los Gatos Blog – our area does not appear to be in these zones)

What to consider when buying a hillside home in Silicon Valley (on the Valley of Heart’s Delight blog)