Rainwater Harvest

 

Welcome to my Water harvesting design

 

Introduction

I started writing up this project in March 2020 whilst stuck in the UK. In September we moved house to live on our little farm in Central Portugal. We immediately got stuck into implementation and with a few alterations, this project is now up and running.

Problem solving

The main problem from the outset is that we want to use less mains water. Portugal has a good mains water supply but this is already under stress and Portugal is among the high risk countries for water scarcity.  In Portugal, water is charged by the cubic metre. It is cheap to start with but understandably gets expensive if you use a lot, i.e. to fill a pool, or irrigate. An alternative supply is therefore required if we are to grow a supply of fruit and vegetables for ourselves, visitors and guests, paying or otherwise. It is a waste of resources to make water fit for drinking then use it to irrigate.

Design Framework – I chose the CEAP design framework to guide me through this design as I feel it suits the land-based project perfectly.

Design tools – SMART goals in the form of a design specification, Venn diagram, Principles, SWOT/C, PMI (Positive, minus, interesting) Maintenance plan. Snipping Tool, Google Maps, and Contour Map Creator.

CEAP framework:

1. Collect site information (and any other relevant info)
2. Evaluate the information
3. Apply permaculture principles and produce a design
4. Plan a schedule of implementation, maintenance, evaluation and tweaking

 

Collecting information

Client/s

Currently the client is just myself and Sarah. But I need to bear in mind that our hope for Chumbaria is for it to become a low-energy sustainable project involving many people. Possible users include:

 

• Us and extended family
• Non-paying and paying visitors
• Volunteers
• WWOOFers and other volunteers *
• Trainees and students
• People with a range of abilities

*WWOOF – World Wide Opportunities in Organic Farming, a global setup putting volunteers in touch with farms looking for some help in return for board and lodgings

Brief

This design considers the use of water on the Quinta. The plan is to be growing vegetables, fruit and have some small animals so a plan for water usage is going to be important. Installation of a polytunnel will also happen as soon as we are there permanently. The current water situation will be investigated, and the design needs to address some wants and needs for the client/s. Expansion from one growing area to full site is envisaged at some point so much will be learnt from this first design. Second reason for this design is to start putting some measures in to combat wild-fires – sadly a real issue in this area of Portugal.

 

I thought it would be useful to look at this project briefly through the lens of the scale of permanence.

 

Bill Mollison’s scale of permanence in order from hardest to change…

1. Climate 2. Landform 3. Water supply 4. Farm roads 5. Plant systems 6. Microclimate 7. Permanent buildings 8. Sub-divisional fences 9. Soil 

 

Climate

The climate here at Chumbaria is certainly different to the one we’re used to in the UK. Generally it is warmer than the UK all year round. As wet or wetter in the winter, and drier in the summer. Typically 750mm of rain per year.

 

A common misconception is that it is sunny and dry all the time. This part of Portugal is not a Mediterranean climate but is dominated by Atlantic weather patterns, diminished by the distance form the coast. As I type (15:00 24th April 2021) I can hardly see across the valley as the rain is coming down in torrents. In January we had three weeks of nights where the temperature dropped to -3°C. In summer there were afternoons it reached 45°C.

Landform

Chumbaria buildings follow the top of a ridge. The land drops away steeply on both sides. The ridge ends just south of our place at the village of Serra do Branco.

 

Contour Map Creator

Water supply

The property is connected to mains water supply. There are two wells lower down the land.

Farm Roads

The road slopes down from the South end and border of Chumbaria, also slopes down from the North end. The lowest point of the road is directly outside Vats house.

Observations of the road reveal that during dry months it is dry, dusty but stable. As wetter seasons come, rivulets form channeling water down randomly onto the land but also collecting at the lowest point occasionally flooding the Vat house. This situation is exacerbated by the lack of guttering to direct the rainfall in a useful direction. The parish president suggested the road could be properly made up if we wished. (We don’t!)

Plant Systems

Currently, grasses and scrub, gorse, ferns and brambles lie below pines and other smaller trees. Eucalyptus dominate the scene, with little or nothing growing below. These effectively hold the slopes and soil in place.

Micro-climates

The shape of the land, a double sloping ridge blocked at one end has many variances in climate. Wind and rain can come from any direction, for many days at a time. We had many frost nights in Jan to -3. When the sun comes out at any time of year, 20 degrees can be reached in a sheltered spot.

Permanent Buildings

All the buildings on the site will remain. All bar the main house need extensive repairs and have no gutters. The main house has gutters clearing roof water to the ground just to the north end of the house.

Fences

There are no fences on the site or at the boundary. There is a small stream (in wet months) adjacent to a cane forest and bramble hedge at the south west corner of the property.

 

Soil

The land on the whole has some thin topsoil where previous growth has been left. Tracks and terraces where topsoil has been removed or covered varies from extremely rocky sandy soil to thick clay. Water runs quickly through the rocky stuff to settle for days in the clay areas.

 

Mains water supply: The current situation at Quinta da Chumbaria is that there is a mains supply of water, currently used for drinking and cooking, washing, and toilets.

 

Wells: There are two wells. On the west side, 30 metres below Rua level, (well 1) an ancient stone built well, in need of repair but it functions as it should. Relatively narrow and shallow, it’s close proximity to a more modern well leaves its function more as a curiosity. Possibly a safety hazard to revisit. Very close to the old well (well 2) there is a more recently constructed cast cement walled well, larger in diameter. This is enclosed and safe. It has a cement inspection hatch.

Using a weighted tape measure and Pi, I calculated that the West well had 15000 litres of water at the end of summer 2019. No water had been taken from it and there is no evidence that other locals use any water from the immediate water table.

 

Image above showing the main well. In the background to the slight right of the hut is the old well. Discovered after some heavy brush cutting. Steve McG 12/9

During the winter 2019, the water table was at ground level and the well would then have 25,000 litres of water.

On the west side, after some scrub clearance, two terraces were cleared to provide some space for veg growing. There is no water supply to this area.

 

The exciting world of Guttering…

Whilst on a ‘Living in Portugal’ forum I came across a discussion on guttering (I know!) The topic was the apparent unavailability of plastic guttering in DIY stores you might find in the UK. A better informed contributor explained that in PT some specialists come, measure up the place and manufacture the required guttering on site, all in aluminium, sealed up on the ground, no joins, then fix up to the roof.

 

The link shows an American company using this amazing system

 

Roll Forming Seamless Gutters

Image of main house. Steve McG 18/12/19

A great source for information on rainwater harvesting:    The Rainwater Harvesting Community

 

Evaluate the information

 

Future use: In the long term, the water system is likely to become complex. Seven houses, three or four community buildings, vermicompost toilets for 30 to 40 people, outdoor kitchen, swimming pool and gardens will all present their own challenges but the immediate challenge will be water availability for plant growth. Extensive use of mains water would cost money and also provide impetus for the pollution industry.

 

Well water might become useful, especially if a requirement for water on the lower west side becomes apparent. Higher up where the veg gardens are and nearer to the buildings zone 1 and 2 it would require energy, probably electrical, to pump the water up. Even solar energy powered pumps must be manufactured and maintained. They also produce noise pollution.

 

Mains water is relatively cheap if used sensibly. The rate increases significantly as more is  consumed. It is a waste to use drinking quality water for sewerage, washing machines and certainly irrigation of gardens etc. So mains water supply should initially be preserved for drinking and showers.

 

Mains water PMI

P: The quality is apparently good (not yet tested for quality or reliability)

M: If there are wildfires locally, the supply can be temporarily reduced or stopped.

I: The cost is relatively low but increases with consumption.

 

Flow rate could be calculated if water were to be pumped out and the refil speed worked out but the following consideration might be made: The water flows from the top of the ridge down to the bottom of the valley, so collecting it at the top makes sense. If a system of rainwater collection is installed which can be easily modified, then some control over flooding and drought should result. A consideration of the east side of the land must be made so any system will need flexibility enabling diversion of water.

 

Well water PMI

P: Free and available

M: Situated at the lowest point of the land

I: Could be used to supplement in arrid times

 

Rainwater

The roof of house 1 is the highest, in good repair and has gutters installed, it makes good economic sense to make the most from the least effort and collect water at the highest spot, keep it up where it is useful and distribute it as appropriate. Eventually it can be integrated into a grey water system, to supply washing machines and toilets but immediately provide the beginnings of a gravity fed irrigation system fed from rainwater harvesting.

Average rainfall for our location is 1048mm per annum ( taken from https://www.meteoblue.com/en/weather/historyclimate/climatemodelled/41.380N-8.200E )

 

House 1 roof is 15 metres by 6 giving 90 m² so potential yield is 94320 litres per year. As can be seen from the table a significant amount of water can be collected.

 

House 1 roof and guttering is in good repair but the fall (slope) is in the wrong direction at both ends of the house so this can be rectified by adjusting existing fittings. The downpipes are at the wrong ends of the house but their repositioning should be relatively straightforward.

 

The first fall of rain washes collected debris from the roof and systems exist that direct this first fall away from the collection system. As the location is rural, this system will not be considered in the initial installation. It can easily be retrofitted if required at a later date.

Portuguese weather can be dramatic and a sudden deluge is not unusual, therefore the pipe diameter needs to be considered. A restriction could cause overflow and remedying the situation could be complicated.

 

The roof has a centre apex so can be thought of as west and east roofs. Currently, the prevailing direction of rainfall is unknown so collection from both sides and flexibility to direct collected water should be possible from the outset. The roof is likely to get a range of debris and bird mess collecting so a system for diverting the first flush of rainfall to prevent contamination will be required.

 

Gravity is a key element in this system. Free, predictable, reliable and underrated, important to this system, so it is important for the water not to lose height unless necessary. In the future it will be necessary to direct water into house 1, so the first collection point (tank)  needs to be above the outlets for the toilet, washing machine etc.

 

Population of the house should average four and the driest time of year is July and August. Four people would typically use 60 litres of water a day for flushing. For July and August that’s 62 x 60l so 4000 litres might be needed. Rain for this period should average 1000 litres leaving a deficit of 3000 not including other water use so 4000 litres of water at this spot would seem sensible.

 

Roof water PMI

P: Large roof areas with HUGE potential

M: Needs repair and additional equipment/work

I: Gutter installation method (see below)

 

I also produced a quick SWOT analysis to examine the relative strengths, weaknesses, opportunities and threats/challenges of all three water sources we have access to.

 

From this point, initially, water needs to be directed to the main growing area on the west side, with provision for the same on the east.

The water storage market was explored and there is a broad range of styles with an attempt at improved aesthetics but the cost is high and even the better looking ones are not great looking.

IBC (Intermediate Bulk Container) tanks seem the ideal solution. They are readily available new, second-hand, sometimes free, and are relatively easy for one person to transport and move around.

 

Empty, they are light so manageable for one or two people, fixings and fittings, taps and connectors are easily obtainable, and they are stackable provided they are placed on a stable base. Aesthetically, they are not pretty, but it would be easy to build a screen to shelter and hide them.

Conclusion

From all the evidence gathered about how to fulfil the needs of vegetable growing and cleaning, general irrigation, water for animals and and redirecting torrents from the road, my conclusion is that rather than pay for mains water, or pump up from the well, it makes best sense to collect water from roofs, starting with house 1. Keeping water at the top of the site maximises its potential to feed irrigation, stand pipes and hoses. It also should maintain a store of water in case of wildfires which are to be addressed in my next design. Effects of diverting rainfall should be monitored but I suspect they will be minimal.

 

Apply permaculture principles and produce a design

 

Considering the ethics and principles, I have produced a Venn diagram, and my wheel of principles. From these I will put together a design specification.  Each point of the spec should fall into one or more of the SMART goals:

 

• Specific
• Measurable
• Accepted
• Realistic
• Time bound

 

 

 

1	Observe and interact	Over a year, heavy rainfall from sky then roofs flowing downhill. Pooling on clay, flooding buildings, creating courses to stream away from the land. Summer is very dry. Come October, greenery bursts out as rain starts again. Travels down the road and pools outside buildings. Well level fluctuates 15 to 25 thousand litres
2	Catch and store energy	Main house roof is a high point on the land. Would make sense to keep water high and use gravity to power the system. This removes the need for electric pumps. Using water from roofs will save the energy spent by the water company making drinkable water. Height x volume = potential energy. Human energy saved placing water where (or above) where required.
3	Obtain a yield	Mains water is charged by the cubic metre, and the price increases with usage. Better to catch rainwater, easier than pumping up from the well? Improve plant / crop yield with reliable controlled irrigation system. Water at Chumbaria will be required for drinking, washing, cooking, swimming, irrigation, sound, plants and animals.
4	Apply self-regulation and accept feedback	Monitor water use over the space (land and time) Review effects of removing and diverting water. Start with small system, but ensure potential for expanding or diverting the system. Listen to users, how to improve.
5	Use and value renewables	Replacing mains water with rain/well water reduces pressure on water company. Water on site is important in case of wildfires. Developing our own supply reduces pollution by requiring less energy used at the water company. In times of fires, the company or fire brigade sometimes cut off village supply so some autonomy for us is important.
6	Produce no waste	Currently, sewage runs into an old well and is emptied when full. This needs to be stopped. Vermicompost toilets will be considered at a later stage. It is a massive waste to irrigate here with drinking quality water. The water system needs a hierarchy of uses: drinking, cooking, dishes, clothes, showers, toilets, animals, plants.
7	Design from patterns to details	Most obvious pattern will be branching as to begin with, there is likely to be one collection point. As the system develops, it might become more web-like. The pattern of this design wheel is helping me to think about the details of the WATER design.
8	Integrate not segregate	Rain/well/mains will all become part of a system fulfilling a range of functions. Grey water also to feature. The system will need to make life easier for people to use.
9	Use small, slow solutions	Make gradual changes to avoid doing too much unnecessary work or wasting money. Instal, monitor, adjust or expand. However, some relatively major work might be essential: Groundwork, roof repairs, guttering, pipe burying.
10	Use and value diversity	The intention is to maximise the diverse water sources into diverse but appropriate functions. A good irrigation system should maximise chances of diverse growth of plants and animals. Diversity of people would include able and less able as all bring value.
11	Use edges and value the marginal	As the land changes (veg, chickens etc) it will be important to monitor life at the edges + what thrives. The ecotone might have a lot of interesting activity. We, as immigrants and permies will be literally and metaphorically living on the edge of the village and society. Interactions will be vital to our community success.
12	Creatively use and respond to change	Build in resilience to extra heavy rainfall and drought. Flow diversion will affect other areas so drier areas can be redefined and used appropriately. Expand / change system whilst monitoring effect. As buildings and roofs are repaired, then the system can be expanded.

 

 

Make a plan

Next, I have used all the information, evaluation and conclusions to produce a design specification. The spec can then be used to evaluate the effectiveness of the design so I will revisit this component after installation.

Design Specification

1. The system must consider and optimise all water sources to keep costs down and be as effective as possible
2. Roof, pipes and gutters must be in good order and capable of handling heavy rainfall – diameter to cope with sudden deluges
3. Gutters must be screened to prevent debris from entering system
4. First flush system must operate effectively to eliminate contaminants form the roof
5. Water must not be taken from the bottom of the tank but from the centre with a filter so debris from the bottom is not disturbed
6. Rainwater storage must collect 4000 litres at house level to supply toilet and washing machine all summer.
7. IBC tanks will be utilised as they are often available for free to be reused
8. Storage tanks must be safe, not be able to topple over if stacked to prevent injury
9. Storage tanks must be easy to maintain and check for leaks
10. Storage tanks must be placed high enough above point of use to provide adequate pressure
11. Storage tanks must not be visible but screened off unless they can be made more aesthetically pleasing
12. All stages of the system need the facility for expansion/modification/replacement
13. Water to be available where needed – close to growing areas
14. All pipes to be of adequate size to transfer water to next part of system
15. Pipes, taps etc must be safe from damage, traffic, sun, digging etc but accessible for maintenance, checking for leaks etc
16. Taps and other access points must be labelled DO NOT DRINK as appropriate
17. Effects due to rainwater harvest must be monitored for adverse effects
18. Consideration must be given to overflow once all storage is full
19. All water made available by this system should be measured to validate its installation costs
20. The system needs to be up and running before summer 2021 to be available for the growing season/s . Preferably installed in the Autumn of 2020 to undergo testing and tweaking through the rainy months.

 

Produce a Design

Here I will describe the design by listing the tasks required to produce the design. It might be that the order of play changes but this is fine.

Installation procedure:

1. Check integrity of main roof and monitor cleanliness – no loose tiles, not covered in bird mess
2. Set the fall angle and direction of existing plastic gutters correctly (or replace with aluminium)
3. Clean gutters out and add gutter screens
4. Connect gutters from both sides of the roof then into first tank/s
5. Install first flush system and check functionality
6. Connect to first level tanks using 50mm dia piping. The tank/s should have at least 3000 – 4000l capacity.
7. Site second level tanks and test for pressure. Choose a site that gives balance between adequate pressure and not being too close to the road. 50mm pipe to be buried under the road.
8. Connect overflow of top tanks to tanks at next level down
9. Install a single jet cold water meter to keep a record of water collected and used
10. Install standpipe for irrigation and hoses

 

 

 

 

Implementation

27th January 2021.

I found a good source of clean IBC tanks from Leiria (our local city) 60 euros each, delivered. Previously held cooking oil and have been pressure washed inside. Metal framed so stackable. I’ve also recovered 100 metres or so of 40mm water pipe, previously used to pump water up from the well to the house, which can be reused. All connecting pipes, taps etc available from the farmers’ supply store.

 

1. We removed gutter downpipes and end caps and changed the slope of the guttering from south – north to north – south then swapped all the downpipes and end caps and refitted.
2. All gutters and pipes were given a good wash but were remarkably clean.
3. Reused/recut the downpipes and with some new 90mm elbows connected the downpipes to the top IBCs.
4. Holes were drilled in the tanks for overflows.
5. We then buried a pipe under the road to connect the overflow of the top two IBCs to the inlet of the one on the next level down towards the polytunnel.
6. The top taps were then opened to flush the pipes out.
7. From the 40mm pipe, three taps and hose pipes were then added.
8. All taps opened to let air out, then closed again to check for leaks – none present.

 

 

 

Maintenance Plan

 

Evaluation of Design Effectiveness

Clearly, the proof will come after implementation but the design specification can be used to evaluate as far as possible. Spec in black, evaluation in red

1. The system must consider and optimise all water sources to keep costs down and be as effective as possible. Yes, after nominal investment in time and money the system works well.
2. Roof, pipes and gutters must be in good order and capable of handling heavy rainfall – diameter to cope with sudden deluges. The system uses 40mm pipe and during heavy rainfall, water could just spill from the top of the tank onto the ground but so far all the excess water has made its way down to the second tank, overflowing away from the house where it can do no harm.
3. Gutters must be screened to prevent debris from entering the system. This has not been easy because of the height at one end, lack of availability of materials for this, and most importantly, the gutters had very little debris. A makeshift filter has been added between downpipes and tanks – sieves and plastic seed potato bags. 
4. First flush system must operate effectively to eliminate contaminants from the roof. Not added at this stage. Debris will be monitored.
5. Water must not be taken from the bottom of the tank but from the centre with a filter so debris from the bottom is not disturbed. Water flows down from overflow (top of the tank)
6. Rainwater storage must collect 4000 litres at house level to supply toilet and washing machine all summer. 4 IBC tanks = 4000L Currently there are two at the top but two more are being delivered any day (mid-March)
7. IBC tanks will be utilised as they are often available for free to be reused. OLX.PT is an online marketplace. Not free – but cheap, and delivered so I don’t need my own truck!
8. Storage tanks must be safe, not be able to topple over if stacked to prevent injury. IBC tanks have built in bases and stackability. The house site has great ground stability.
9. Storage tanks must be easy to maintain and check for leaks. The arrangement of tanks provides easy access to valves, taps etc. No joints are buried as they are most prone to leaks.
10. Storage tanks must be placed high enough above the point of use to provide adequate pressure. The pressure is fine. Less at the polytunnel but perfectly adequate. 
11. Storage tanks must not be visible but screened off unless they can be made more aesthetically pleasing. Currently they are visible but once the next two are installed a screen will be constructed from eucy and canes.
12. All stages of the system need the facility for expansion/modification/replacement. Yes, all in the design. Space at each site for expansion.
13. Water to be available where needed – close to growing areas. Yes. All very convenient!
14. All pipes to be of adequate size to transfer water to next part of system. 40mm has been fine so far. 
15. Pipes, taps etc must be safe from damage, traffic, sun, digging etc but accessible for maintenance, checking for leaks etc. Burying under the road, and identifying marks. All joints to be above surface, easy to see/check.
16. Taps and other access points must be labelled DO NOT DRINK as appropriate. Safety signs to be made and installed/checked. 
17. Effects due to rainwater harvest must be monitored for adverse effects. Observe carefully.
18. Consideration must be given to overflow once all storage is full. See 14.
19. All water made available by this system should be measured to validate its installation costs. See point 1.
20. The system needs to be up and running before summer 2021 to be available for the growing season/s . Preferably installed in the Autumn of 2020 to undergo testing and tweaking through the rainy months. YES! Installed and running at the end of January. 

 

Tweaking

 

Alterations to the design…

As nothing is happening on the east side of the land, I have not directed water that way yet, but this will be easy to do when appropriate.

I will not stack the tanks, more ground space has been allocated so they can go side by side, and will be safer.

Two more tanks will be added on the second level. More storage and there is plenty of space down there.

The tanks will be wrapped in black plastic to exclude light and  prevent algae growth.

I added a main tap at the end of the 40mm pipe so that the hoses are not constantly pressurised. Also, I can switch a section off to work on it or extend or whatever.

A hose has been added at the top so plants around the house can easily be watered. This syphons just from the top 300mm of the tank so if someone leaves it on it will not drain the whole tank.

 

Conclusions

The installation part was really good fun! The system has worked really well. The night after installation it rained and each tank collected 700 litres.

With a hose at every level it makes watering a pleasure, easy for anyone to do. The taps are easy to see and operate.

Regular watering should improve yield and already, there is a lot of veg growth.

Towards the end of Feb a man came and disconnected the water supply with no explanation ( a mix up down to Portuguese bureaucracy ) and we had no supply for 10 days. Our trusty IBCs kept us in water for all bar drinking so they came in exceptionally useful.

The system is really easy to adapt, extend and modify. Now I’ve spent many hours rummaging through the boxes and shelves at the local farm store, I’m a bit of an expert on plastic and brass connectors, 40mm, 32mm, 15mm pipes, connectors, reducers etc etc.

 

Reflection on Theory, Design tools, and Processes 

 

CEAP framework: In normal circumstances (not COVID-19 lockdown) I might have used SADIM or similar. It helped me to keep the Collect, and Evaluate stages more clearly defined. I’ve spent a lot of time thinking about this design and could easily start going round in circles!

 

SMART goals and design specification: It is too easy to write a goal that is hard to measure. How can we measure the success of a design without some clear targets? From my Design Technology days, we always develop spec points that we can, at some point in the future use as a measure of success.

Venn diagrams are interesting as we can consider where the ethics have been addressed, but also, where and how they interact!

Principles: This was a vital tool and I used/developed it over the year of observation. I do feel that I’ve only considered the principles in their most obvious (to me) sense but with this particular project it’s enough. I put the wheel together as I wanted to produce something fun, visually interesting, and who doesn’t love to do a bit of colouring in?

Yeomans’ scale of permanence I’d not heard of before but interesting to relate it to Chumbaria. This helped me think about the elements of the village and what can / cannot be changed and why.

SWOT/C and PMI: Useful, quick and easy to apply. Draws some unexpected observations out, such as opportunities for using wells!

Maintenance plan: Essential of course and important to think about the people involved. Water has health and safety implications so this plan is mandatory.

Snipping tool: A handy Windows tool to grab an image from the desktop.

Google Maps/Earth: Not just for navigation, but also handy to use 3D for an idea of topography. Layers tool to view land features is useful, and although it is not used in this design, it can be interesting or valuable to view the land using ‘historical imagery’.

Contour map creator: A great free tool that can be used to add topographical lines onto any region on the planet. The lines can be set to 1m, 2m 5m etc apart.

 

Yesterday, I didn’t wake up thinking that I would redesign and paint my workshop but that’s what I ended up doing. Whilst doing this, I was listening to Geoff Lawtons’s brilliant lecture he gave on understanding the mighty tome that is Bill Mollison’s  Permaculture: A Designer’s Manual. In this lecture, he really digs into how to read, understand and apply the information in this potentially scary book. Key points he brought up were aims, principles, patterns, and I now know I need to have a good read to deepen my understanding.

 

Link to Geoff’s lecture (just over an hour…)

https://www.youtube.com/watch?v=oUIGzy0bqFY&t=2751s

 

 

 

Next Steps

 

Technical skills I had planned: Sadly, the May Cob course in Brighton has been cancelled and Ben Law’s Roundwood Timber Framing course has suffered the same fate.

 

Update 15th November 2020

We arrived in Portugal 16th September and were busy making home and doing some work preparing veg beds until I had an accident on my bike and broke my left leg. This has, on the whole, put me out of action but before this happened, a 6m x 3m polytunnel went up. I also bought 3 IBCs, installed one IBC at the level just below the road on the West side. I connected this via 40mm piping to a garden hose. The IBC was filled from the mains supply tap but now we can water plants in the polytunnel and on the veg patch without trailing the hose across the road. The tank is now wrapped in black plastic to prevent algae growth.

 

Update 27/01/21

I’m back on my feet after the accident and have assistance from a friend. We bought some decent ladders and after a patch of freezing weather, managed to get out and make some progress on this design.

We salvaged some 40mm polypropylene water pipe that was previously used to transport water up from the well to the house in a time before mains water supply.

As water is currently only required on the west side, the east will be ignored for now. In any case, it will just be a mirror of the west. A shallow trench was dug across the road and the pipe buried. We removed the gutter downpipes and end-caps and swapped them and the gutter gradient to the south end of the house. We then refitted the old pipes to connect one IBC at the end of the house and the buried pipe connects the IBC tanks. Inspection of the gutters showed very little debris so after a quick clean a simple filter was fitted to the downpipe.

 

When it rains again, I will need to monitor flow rate, effectiveness of the filter, and check for leaks although most of the system is not subject to much pressure.

 

In theory, the water should flow to the south end of the gutter, down the pipe, via the filter into the first tank. Once the tank is full to the level of the outflow, water should travel under the road down to the second tank. Once this is full, water will just overflow onto the ground but be directed out of harm’s way.

The system lends itself to adaptation and expansion as required.