Groundwater Woes
Part 2
By Andrea Peck
I am hoping that many of you took the challenge and found out where your water is coming from. From the research that I've done, I see that the majority of us in SLO county (and the country, for that matter) get at least a smidgen of our water from groundwater sources. To top it off, if my mental scratchpad serves me correctly, I do remember reading that the majority of surface water sources (such as lakes, reservoirs, and rivers) are fed by groundwater. So, either way you look at it, you are probably using groundwater daily.
The world is comprised of 70% water, so you may wonder – what is the problem? Well, the vast majority (97.5%) of that water is ocean (salty) water that is unusable. The remaining 2.5% is fresh water. Only 1% of this available water is usable. The rest is inaccessible or just plain too dirty to drink.
That's it. That's why they call it precious.
This is important because we need to be aware that when we dispense our water it is either replenishing the groundwater or it is not. The thing that dawned on me like a ton of bricks was that water that is on the surface tends to evaporate and water that accumulates often leads to run off. Much of our water is not percolating back into the soil; it is floating up into the sky or sheeting off into the ocean. Yes, it may continue the water cycle by evaporation, but have you experienced our winds? Do you really think a bunch of blowy moisture is immune to being shoved over to the next continent? Plus, water that runs down roads and gutters brings nasty bits of pollution with it which impacts native wildlife and marine ecosystems.
I began to consider that this may be why the experts are continually going on about groundwater levels and water tables and the like. Though the water will end up coming back as rain through the water cycle, it may not end up on our soils or more importantly, at our tap – it may end up somewhere else.
It was kind of an “aha” moment.
The conclusion is clear: we need to keep as much water as we can on our property where it can sink down through the rocky fissures that allow our water to collect underground.
How do we do this? Well, certainly you can see that letting rain drip onto patios or driveways and then run into the street is counterproductive.
Rainwater catchment systems are probably the simplest mechanism you can install to curtail rainwater runoff – the water does not even need to be used in any particular manner – as long as it is allowed to permeate soil instead of concrete, you are increasing our chances of replacing groundwater. Remember that familiar estimate: a 1000 square-foot home can generate 600 gallons of water during a 1” rain.
In fact, this method is so effective that many places, Los Angeles included, are considering making rainwater catchment systems mandatory in new developments. (See link below).
There are also flexible rainwater extenders that can be moved to allow roof runoff to percolate into soil. It is important to remember that roof runoff is not appropriate for most edibles because of the particulate matter, bird feces and other detritus that comes from the roof itself, so it is best to place your water into an area that contains ornamentals. Where there is just plain dirt, try a cover of mulch to increase permeability. What the heck, while you're at it, add a drought tolerant shrubbery as a reward.
There are many methods that increase your “groundwater percolation rate.” One idea is to replace existing lawns with native or prairie-type plants. Native plants have extensive root systems that pull water in and clean it by filtering out pollutants (similar to an estuary). Lawns, on the other hand, do not have a strong water-retaining capability.
Replacing a portion of your driveway with gravel that allows water to seep down is another solution for those who are looking for a large, workout-style project.
Pavers are great replacements for patio areas because water can permeate through the connecting points.
Remember your voracious washing machine? Though there are caveats when using this water, (it cannot be stored or used on edibles) setting it up as a grey water system will replenish groundwater supplies.
The point is, the vast majority of us are using groundwater in one way or another. Being thoughtful in regards to our use of water, along with replenishing groundwater is part of the new mindset that we as a culture need to adopt.
Check out this link to see how water catchment systems are the new home accessory:
http://www.treehugger.com/clean-water/los-angeles-may-get-mandatory-rainwater-harvesting-law.html