Groundwater Re-charging

It’s a rainy Monsoon day.

Today, it’s water, water everywhere, but soon there will not be a drop to drink. Think forward to April & May. Dry times ahead. And for some, water problems could come as early as February & March.

Every monsoon, Goa receives around 3000mm of Monsoon rainwater.

That’s a lot. In fact, it’s plenty, and more. So why are we faced with dwindling water tables, empty wells, the “need” for damaging bore wells to compete with all the other wells, and the resulting mafioso-like sale and tanker transport of fresh water?

Water is one of the most important resources we have. It is the beginning of all life, and if poorly managed, can lead to drought or devastating floods, bringing life to an abrupt end.

Often the instant reflex to water falling on land is, “Quick! Get rid of it!”. Every effort is made to keep the property “dry”, to prevent water from entering the property from higher points, and ensure the speedy drainage off the property on lower points. You can see this applied in apartment blocks in urban settings where the spaces are entirely paved, in gated complexes, in single-family homes, gardens, and surprisingly, even across paddy fields and other agricultural lands. A glaring and painful example is the paddy field in front of our home, that had a long ditch carved into it a few years ago to carry so much of the water away.

But what happens next? Does the water just get rerouted to another place to cause havoc? Or does it continue racing down and out through nalas (storm-water drains) and other drains, across fields (many fallow), into bursting rivers and straight out to sea, where it’s of no use to people, land or animals?

When we hear the term “rainwater harvesting” what can come to mind is a collection of opportunistic recycled plastic tubs or more organized systems of storage (which can work really well for climates where the rainfall is spread much more evenly throughout the year) or vast, expensive concrete tanks for places where it rains in buckets.

In Goa, it rains, and rains and rains. Calculate the rainfall received in the monsoon months, and the water requirement for humans, animals and land for the rest of the year and you’ll see that the hard-storage of rain water could turn into a resource heavy, expensive, and ecologically disruptive endeavor.

What is the solution? Enter rainwater harvesting for re-charging groundwater.

The very best place to store large quantities of water is in the land itself. In the soil, in the organic matter and via the micro-organisms that are in the soil. By way of the trees & vegetation, and their roots & foliage. And down into the underground water table itself.

There are many techniques that can be used for rainwater ground re-charging according to situation, and many that can be used together to create an effective and resilient system. Before addressing those specifically, the six most important words you can retain are:

“Slow, Spread, Sink…..Mulch, Mulch, Mulch”

Slow.

When water runs over the land quickly it doesn’t have time to soak in and races over and off the land carrying off any accumulated topsoil, organic matter and silt with it. It can create crevasses and gullies which may not be in places that help you or the land. It also carries these materials off to our waterways which creates entirely another set of problems. That’s erosion, and it’s one of the biggest problems of our time. Without soil, there is nothing.

Spread.

Imagine the water coming onto your property and how essential it is to human & earth health. Does it seem prudent to let it race in and race right off the property, leaving a wake of destruction in it’s path? Would it seem wisest to use every last drop before it eventually may (if it has to!) leave your property? Imagine a system where the water is slowed upon entry or even before, has time to drop any silt or organic matter that it may have been carrying, and is spread out to appropriate parts of the property, where it can be of maximum benefit, and minimum destruction.

Sink.

Once the water has been Slowed and Spread, it then has time to sink into the land. It will be held in the soil for longer and replenish both the immediate and surrounding natural water systems.

Mulch, mulch, mulch.

Although we’re talking about it last, these are probably the three most important words for any improvements that you can make to soil or water: “Mulch, Mulch, Mulch”. Keep in mind, though, that if you don’t take “Slow, Spread & Sink” into account, much of the benefits of mulching will be simply washed away.

What is Mulch? It is any type of material that is spread or laid over the surface of the soil as a protective covering.

Mulch can be either in the form of a living mulch, growing in and over the ground, or a layer of mulch material on top of the soil, for example dry leaves.

In addition to the many other critical benefits of mulch, the more organic matter you have on top of your soil, and breaking down and moving into your soil, the slower your water will travel and the more able the soil is to soak it all up. Organic matter in the soil acts like a giant sponge and increases the moisture holding function of soil by as much as six times or more, depending on your soil and how much organic matter it does or doesn’t already have in it. Mulch also means that there will be more macro & microorganisms, fungi & mycelium, all working for you to hold and transport moisture in the soil.

Some other important things to keep in mind when thinking about how water moves around your property:

– Where is the water coming from? Direct rainfall? Or also catching the natural watershed, eg. from a hill above? Is a hard surface, like a road, a driveway or a roof, also directing more water on to your property?

– Where is the water finally going? Are you currently or potentially able to soak it all in? Or are you receiving so much that you need to ensure the safe exit of water from your property?

Has the water worked as hard as it can for you before it leaves the property?

– Just as sealed, paved and concreted areas do not allow for water to soak back into the land, even unpaved paths, roads or high traffic courtyards do not soak water in. They become heavily compacted by feet and wheels and end up behaving like sealed surfaces.

– Compacted agricultural soils do not allow water to soak in. Soils become compacted when they are low in organic matter, left open to the elements (baking sun and and lashings of monsoon rain), and have had their soil life destroyed due to chemicals, burning and other poor practices.

– Mosquitoes: Will holding water in my soil breed mosquitoes?

No. Mosquitoes breed in stagnant water. Any puddles that may form will quickly soak into the ground. There will not be time for a suitable mosquito breeding ground to establish in a well designed and executed system.

All of the considerations above are relevant to both large and small properties, in both rural and urban settings. The techniques and scope may differ, but the principles will remain the same.
Hopefully, this information will be good food for thought for then going on to learn about and consider the various techniques that may suit your circumstances, and a way of working towards Goa’s water and food security.

Rosie and Peter have regenerated a piece of degraded land in Goa, India, to become an abundant and productive Kitchen Garden and Food Forest which thrives as part of a sustainable and resilient ecosystem. The garden serves our own food needs, provides a surplus for friends, and serves for demonstration & education, and research and development purposes. We are actively involved in awareness and outreach to individuals and organisations who wish to participate in every aspect of local food security.

https://www.facebook.com/RosieAndPeter

I also founded, admin & animate the “Permaculture Goa” Facebook group.

You can find Rosie’s profile on Permaculture Global here.

Related

Popular

3 thoughts on “Groundwater Re-charging

Leave a Reply

Your email address will not be published. Required fields are marked *