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My Garden Watering System

3 April 2019

A brief one topic post on a subject requested by a blog reader (thanks Chris). The need for a watering system in tropical northeast Thailand may come as a surprise to some readers who haven’t lived through the annual cycle of wet and dry. It certainly did for me and this is how we cope with months of drought.

An Introduction

I need to firstly point out that this post is based on the climate in the northeast of Thailand (top right on a map), which is different to the south and the tourist coastal areas. Both regions have dry periods, but I haven’t lived in the south long enough to describe that weather pattern.

When I moved to Thailand I came from a background that had never experienced living in a tropical climate. My home town of Canberra in Australia is mostly incredibly dry and our gardens (and people!) only survive with access to large man-made dams. Outside the city the landscape is often uniformly brown and arid.

Cotter dam just outside Canberra, one of the water supplies that have made the city drought-proof (in theory).

My vague uninformed vision of Thailand was one based on endless lush greenery and tropical greenness, which by its nature would indicate lots of rainfall. Wrong.

The well known description of Thailand’s weather is ‘hot and dry’ and ‘hot and wet’, which may apply more to the southern provinces than us. In the northeast we are a little more varied in that the dry and wet happens but we also get a cooler period from November to February. Leaving aside temperature, the cool season also marks the end of rainfall until the wet season arrives in May, which is six months of very little rain. In fact during the cool season itself Nov – Feb, it is unusual to get ANY rain. In March and onwards you will get the occasional downpour but this doesn’t become a regular relief for the garden until later. My post ‘Thailand is HOT’ HERE, included some graphs more aimed at the heat but here’s one relating to the rainfall in Nong Bua Lamphu, which is the province we live in:

The dry season is very obvious.

The outcome of this introduction is that if you are serious about developing a larger tropical garden that requires you to do more than just a bit of hand watering then you do need an equally serious commitment to some sort of watering system. In our case we have gone with a sprinkler system and this post shows you what it looks like.

I am sure many of you have already seen many photos of the garden but let me tell you that without a watering system we would be either spending hours a day hand watering or this display of greenery wouldn’t be happening for me to share with you.

The Watering System

Firstly we went with a sprinkler rather than a dripper system because of the density of the plantings. If you have a garden that has an emphasis on individual shrubs, trees or rows of vegetables then a dripper system works well. However, our garden is massed planting over large areas, as you can see from the photos, and drippers just wouldn’t work effectively for us. Our ground cover is particularly thick and widespread because Gaun used this approach to defeat the weeds, that otherwise would have taken over everything. Apart from a few climbing weeds that poke through we get almost NO weeds in gardens that cover a bit under a rai (1,600 mtr2)

We use bore/well water and this is key to everything. For those on village water forget maintaining a water hungry garden. We get through maybe 8,000 litres plus each session, which would be the entire village’s usage for the week 🙂 We have a submersible pump that feeds a 2,000 litre holding tank and then two pumps distribute the water to the gardens from there. A smaller pump supplies the six garden taps and this one is automatic turning on and off with tap usage.

A large manual pump feeds the sprinkler system with 58 outlets split into seven zones, as well as seven other taps. The procedure is to turn on one or two zones and then switch the pump on. Ten minutes does the job. For double the price we could have bought an automatic pump. This pump has the capacity to power maybe 20 sprinklers or more at a time, which in theory means you could water the whole garden in the three sessions. The reality is that the holding tank and submersible can’t keep up with the demand and the pump will run dry with that many sprinklers on at the same time. Cha Cha (slowly, slowly). It’s Thaitime and what else have I got to do 🙂

The foundation to the system. A 2,000 litre tank and the main pump. Do you like the Thai-style support arrangement? Having seen the photo I will do something about that (one day).

The water feeding from the tank to the pump and garden – left. Separate valves to turn off the flow and open a pipe for cleaning – right.

For the technically minded.

A 1 1/2 inch pipe was laid down both sides and across the back of the new tropical garden as the main supply line.

This pump also supplies water to a sprinkler system in the original garden. The main feed pipe for this zone is 1 inch rather than the 1 1/2 going to the new garden.

This area is covered by the one zone of 9 sprinklers so the smaller feeding line does the job.

The main 1 1/2 inch line provides water to 3/4 inch sized pipe that ends up at these tap/sprinkler valve combinations. The tap has a little gravity pressure without the pump but for hand watering purposes it only gets going once the pump is turned on.

A closer view of the fittings that make this combination happen. Super cheap and easy to do. Most of the couplings are 4 – 5 baht each. The valves are under 50 baht and a tap under 100 baht.

The uprights for the sprinklers are 1/2 inch pipes. You can buy the connectors that have 3/4 inch one side and 1/2 inch the other. The sprinklers are found at Global House or Thai Watsadu as well as some local hardware shops. These ones cost 100 baht for ten.

3/4 inch pipe connectors leading to other sprinkler outlets. A bit of glue and slide them together. Dead easy.

I have painted most of the visible pipes green to reduce their visible effect, but I’m a bit over enthusiastic in that sort of thing.

I hope you enjoyed this post. Please leave a comment. It makes my day.

2 Comments

  1. John Tryon

    I must say that I envy your garden accomplishments. I don’t have the”support” in labor provided by Guan so my efforts are pared back immensely from your beautiful diversity. One thing different for me at this point, I elevated 3 storage tanks 5 meters high and use gravity feed to all hose bibs. If/when I expand as you have done I will add pumping power to operate the sprinklers

    Reply
    • Tony in Thailand

      John, I would be in the same situation without Gaun. I would still have a garden but it would be a lot simpler than what we have because I just don’t have the ability to work in this heat as Gaun does nor do I have the physical capacity that I did a few years back. I think the elevated tanks are a good idea to feed hoses and maybe a dripper systems for specific plants. If you are into mass planting, as Gaun has done, then the drippers are less useful and as you state a powered sprinkler system is the answer. The raised tanks are great for power outages too. We had one for a couple of hours this afternoon (very unusual in our village luckily) and of course we then lose access to water along with everything else.

      Reply

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