Groundwater flows not significant | Letter to the editor

To the editor:

Here are corrections to the misinformation about Bainbridge Island’s groundwater supply published in a recent letter: The following quote is not accurate.

“… much of the water pulled from municipal wells (on Bainbridge) originates in the Olympic Peninsula, traveling in aquifers under the Sound.”

It is a fact there are similar aquifer bearing geologic units on the Kitsap Peninsula and Bainbridge Island. However, it is only inferred that these units are connected, and groundwater in the Kitsap Peninsula aquifers travels to Bainbridge aquifers below the Puget Sound uninterrupted. There is no direct evidence of a “magic underground river” flowing from the Olympic Mountains, which are approximately 30 to 40 miles to the west beyond the Kitsap Peninsula and the Puget Sound.

The city hired the U.S. Geological Survey (USGS) to evaluate the water supply, which is primarily from groundwater. The 2011 USGS report concluded the following (p. 91):

“Groundwater flow to Bainbridge Island accounted for about 1,000 acre-ft/yr, or slightly more than 5 percent of the recharge amounts.” This means that, at most, only about 5 percent of the groundwater recharge to Bainbridge aquifers could be coming from Kitsap Peninsula aquifers.

Moreover, the USGS further predicts that as growth continues to 2035, the groundwater flow direction in the deep Fletcher Bay Aquifer (which currently supplies 1/3 of Bainbridge’s drinking water) will likely reverse and move east to west, meaning the inferred 5 percent contribution from Kitsap Peninsula could be negligible.

Lastly, there is an enormous amount of pumping already in progress from production wells on the Kitsap Peninsula. Just 60 of the many Kitsap Peninsula production wells are producing approximately 30,000 gallons per minute. This extraction with projected growth severely reduces the potential migration of groundwater to Bainbridge Island.

Therefore, based on the USGS study and current Kitsap Peninsula pumping data, it is clear there is no significant contribution of groundwater from the Kitsap Peninsula — or any other off-island source — that Bainbridge residents can rely on. This is why Bainbridge is classified as an EPA Sole Source Aquifer.


Bainbridge Island

More in Letters to the Editor

Let’s do our part and make things right | Letter to the editor

To the editor: Lawmakers in Olympia plan to balance the tax system… Continue reading

Taxes are the least of Trump’s problems | Letter to the editor

To the editor: I agree with Mr. Sheldon (“Asking for Trump tax… Continue reading

People must act on global climate change | Letter to the editor

To the editor: Listening this week to an NPR interview of Nathaniel… Continue reading

Sad farewell to our library’s plum trees | Letter to the editor

To the editor: It is with great sadness that we and the… Continue reading

There will be a big thank you, believe me | Letter to the editor

To the editor: So, Trump said — I gave John McCain the… Continue reading

Asking for Trump tax returns isn’t American | Letter to the editor

To the editor: I was surprised finding out of this attempt at… Continue reading

Contact Congress to oppose Trump budget | Letter to the editor

To the editor: I was happy to see the response to President… Continue reading

Too much television during executive time | Letter to the editor

To the editor: Trump shouldn’t have time to watch SNL, much less… Continue reading

More transparency needed on admissions | Letter to the editor

To the editor: The college admissions scandal has captured the nation. There… Continue reading

Don’t cut budget for safety net programs | Letter to the editor

To the editor: The President’s budget proposal demands a response from each… Continue reading

Peltier’s enemies are out to get him | Letter to the editor

To the editor: I’ve been a resident of Bainbridge Island for almost… Continue reading

For a stronger, more inclusive community | Letter to the editor

To the editor: March is Developmental Disabilities Awareness month. President Ronald Reagan… Continue reading