Rain water harvesting in a leafy London suburb

If its London, it must be raining ! This is the common thought that runs through most people's minds, so then where does the question of rain water harvesting arise?  Rainwater harvesting for me a journalist out of India is meant for countries with fresh water scarcity issues. Obviously that was an ignorant supposition as wasting of valuable rain water can happen anywhere in the world.  

Chatting with a London resident who lives in the leafy  London suburb of Woking, one finds that a system of 'harvesting' the rain has existed for decades here in London and he took me around his 100 year old home in Woking to explain the system.

"In Woking there is a system called a  soakaway where building regulations require you to adequately dispose of stormwater from the building. To try and ensure water is dispersed into the ground evenly and quickly you must consider the use of a soakaway in all homes, according to the council," explains David.

" You must use a soakaway, if design criteria can be met. Discharging stormwater into a drain will only be allowed if soakaways or other infiltration into the soil, methods are not suitable," said David.

So we were curious to know how  do soakaways work? Soakaways store the immediate stormwater run-off to allow infiltration into the adjacent soil. Then, they  must discharge their stored water sufficiently quickly, to provide the necessary capacity to receive run-off from a subsequent storm. The time taken for discharge depends upon the soakaway shape and size and the surrounding soil's capacity to absorb. Soakaways can be constructed in many different forms and from a range of materials .

Interestingly one cannot just build a soakaway without first checking if a soakaway is the most suitable means of disposing of stormwater. That is done by checking if the soil around the building can absorb water; the site is not on filled ground; the site does not slope towards the building and; the water table is not too high already. Other rules are that  soakaways can be sited at least 5m from any buildings and if one is close to boundaries the neighbour should be consulted.

The council gives guidelines which are interesting to read up on, regarding the building of the Soakaway In most cases where the soil drains well, and the roof area is less than 100m2, you will be able to construct an open chamber type soakaway, as follows:

Calculate the roof area to be drained into each soakaway. Then calculate the volume of the soakaway:

Roof area in m2 divided by 40 = Volume of soakaway in m3 (AxBxC)
The volume can then be measured below the incoming pipe and above top of foundation.

The council is particular that the  residents ask for an inspection of the drainage and the soakaway while it is being constructed.

David's soakaway was in the middle of his lawn! Well, if this can be done in London, why ever not elsewhere right?

Marianne de Nazareth

Alliance for the Rain Movement

“Success will be bigger if we work together”, said Vessela Monta, executive director to International Rainwater Harvesting Alliance (IRHA), at a meeting held on 28 November 2013. Representatives of different organizations with a sole motive to establish Nepal Rainwater Harvesting Alliance (NeRHA) were present in the meeting. The alliance aims to suppress the feeling of competition among those participating organizations and bring them together for better outcomes in Rainwater Harvesting aspects of Nepal.

As the alliance is in starting phase, agendas on network criteria and necessities were discussed and prioritized. After the discussion among the participants, a scoping team of 5 members has been formed. Meeting to be held once in every two months is also decided and agreed. The profiling of all the activities related to rainwater harvesting practices by the member organizations was decided by the meeting. Along with this advocacy through newsletters and information dissemination in the website will be initiated. 

As it is going to take time for binding and shaping up the other functions of the alliance, Lumanti will act as Secretariat of the alliance until the alliance is registered according to the NGO’s rules and regulations of Nepal. 

Government shall be invited as an advisor rather than being involved in the networking aspect of the alliance. The meeting adjourned to be held on 31 January 2014 and a work plan shall be discussed next. 

By Bimala Gurung

Harvesting Rain for Terrace Farming

With the growing consensus among the city dwellers about the organic farming on the rooftop recently an exhibition for the promotion of terrace farming was held as a possible alternative way to maintain greenery, manage the solid waste and good security by the Kathmandu Metropolitan City.

Inaugurating the event Deputy Minister Prakash Man Singh advocated in favor of providing environment for the further promotion of terrace farming. The exhibition showcased different technologies for recycling, waste treatment, irrigation, organic farming along with the low cost water harvesting technology for sustaining farming practices.

With the concept of utilizing rainwater for terrace farming and other household purposes a model of Rainwater Harvesting system along with the treatment system and reuse of wastewater was demonstrated by Niva Rain in collaboration with Guthi, a member of Nepal Rainwater Harvesting Alliance (NeRHA). Visitors who were positive regarding the framing practice became even more enthusiastic when they were introduced with the rainwater harvesting system as it seems promising in delivering rainwater to fulfill their greenery mission.

Rainwater harvesting demonstration presented complete solution for the collection, storage, purification and reclamation of water for the mass of people who were still in confusion regarding the installation of system. The reclamation of water through constructed wetland along with the purification of water through Bio-sand filter provided answer to the queries of visitors who believed harvesting is for temporary only. Further limelight to the exhibition stall was added by Narendra Man Dongol who himself has installed the system and has been living on rainwater. His daily water demand and yearly saving on water was even more exemplary for the visitors.

With the water demand of 1200 liters per day, supplied through reclaimed water, 700 liters and rest 500 liters from the rainwater he has been able to save Rs.5000 per month. Amazed with the figures Niraj Dongol one of the visitors said that “dream of Kathmandu city as sustaining eco city seems to be possible, when every drops of rain are used in blooming every seeds through harvesting practice.”

The stall not only grabbed the attention through cost effective technologies but also introduced portable sack tank commercially known as ‘BOB’. The sack tank is easy to transport and weighs only 3.5kgs when empty. It can fit into an airline hand carry bag when folded and despite its size; it has a capacity to hold 1400 liters of water. The outer bag of sack tank is UV resistant woven polypropylene and the liner is 100% virgin polyethylene- a material that is approved for contact with food. The cost of this tank is NPR 5 per liter. While comparing this with the Reinforcement Concrete (RCC) tank that costs NPR 30 per liter and PVC black tank that costs NPR 11 per liter.

For the tenants who could not harvest their share of rainwater due to lack of space now can claim their share of water, informed Prakash Amatya, a member of NeRHA. For those who depend on still water of dug well, can now enjoy the fresh shower through harvesting of rainwater. Since this bag is portable, it could be used in monsoon months only and wrapped up for the rest of the season.

Excited with this new innovation Purna Limbu said, “Rainwater harvesting has always been alternative for the water crisis but this water bag has been alternative to the space crisis also, now everyone can have easy access to rain water”

Really, rainwater has been boon to the existence of living organisms, needless to say what its importance is in our daily life however, at the recent time when the world is facing serious water woes rainwater harvesting plays a vital role in reducing extraction of ground water to increment in ground water table. Considering this utility of rainwater we need to harvest  every single drop of water not only harvest rather also reclaim it so we could fully trust on rainwater, which  is not so herculean task just the right blend of available technology. If Narendra can depend on rainwater through this technology then why can’t we?

By Neha Basnet

Aalkohiti blesses no more!!

A stone spout once a model of conservation to many other stone spout and community initiatives is now looking for more efficient system that would revive it. Aalkohiti is dying, having the history of more than 1600 years, Aalkohiti has seen many prosperous and adverse years, and at times it gave life- water to majority of residents near it but now with starting of dry season the hiti itself is dying. Like all other hitis of Kathmandu this historic stone spout was counting its days to extinct however people from the surrounding community gave it life by ensuring continuous recharge of water to flow via Rainwater Harvesting, and gave it a modern twist by supplying water to 200 household ensuring the accountability of the water users to conserve the stone spout.

Aalkohiti

pond next to aalkohiti at present

Supported by various organizations, Aalkohiti conservation was initiated by the locals giving it life. Once people discovered the water in the hiti comes only if ground water is recharged, people concluded in artificially recharging groundwater by collecting rainwater of the 300m long pavement. “Two recharge structures were constructed, but at the moment one has been buried as it is no longer recharging while we are also facing problems in recharging via remaining recharging well, resulting in lesser recharge of rainwater,” shared Mr. Sushil Shrestha, a pioneer in conservation of Aalkohiti.

For more than a decade the recharge structure served to conserve Aalkohiti and supply water to more than 200 families in the locality through pipelines and hundreds of other families who collected water without any hindrance except in the dry season. “It was routine that Aalkohiti would dry during the dry season almost for two months, but this year the hiti has dried a month earlier probing acute shortage of water in the locality,” said Anil Shrestha a local resident.

While it is obvious that water source would dry up during the dry season, this time rise in temperature has played its significant role, meanwhile the less recharge of the water during rainy season is another reason that Aalkohiti is not serving people a month earlier than its usual routine. “The situation is being routine these years as we have buried one recharge structure and water recharging has slowed sown in another recharging well,” analysed Mr. Sushil. According to him the recharge well are being jammed with the mud from around the well and blocking the passage of the water as it has closed the pores of the gravel, resulting in less recharge. It is vital that we check and maintain our recharging system and also look for more efficient way to recharge, he added.

The in depth analysis is yet to be done, but for the moment the consequence is Aalkohiti has dried up before the regular time. People are now forced to buy water from the tanker to serve their ends while the functioning of the recharge structures is still questionable.

No doubt, with the adaptation of Rainwater harvesting and Artificial Groundwater recharge, Aalkohiti blessed many. Setting an example, success story of Aalkohiti inspired many other communities to adapt rainwater harvesting for the conservation of the Stone spouts. But at the mean time it has again pressed all other communities to look into the system and check if their system is working properly.

But reality is Aalkohiti has not blessed now due to some shortcomings, it is vital to rectify the loopholes, correct it, if one wants to be blessed with Aalkohiti for ages.

Rain water harvesting in the Henry Doorly Zoo, Omaha,USA

Two warm days in the middle of winter in Omaha? There was no way we were going to waste them. So off we went to the Henry Doorly Zoo, which according to its credits, it is the best zoo in the world. Standing in line with the chill wind buffeting us, we heard the majestic and reverberating roar of a huge cat from somewhere within an enclosure to our left. Could it have been a Bengal Tiger we wondered? We were definitely going to the Big Cat enclosure later. I mean who would have thought to see a zoo in the mid west of all places?

It was in the third area that we chose to visit-- the Desert Dome, we saw the world's largest indoor desert, located under a glazed geodesic dome which is a landmark icon of the zoo and for Omaha. Built at a cost of $31.5 million, the dome has plant and animal life from three deserts: The Namib desert of Africa, the Red Center of Australia and the Sonoran Desert of the southwest of the US.

The awe inspiring dome is 230 feet in diameter spanning over one acre, and is an engineering marvel as there are no supports to it. Standing 13 stories tall, the top of the dome is 137 feet above the columns. Geodesic means is a dome pattern of triangles that actually provide a strong structure. Interestingly, a gutter system, on the outside of the dome, is connected to two, 20,000 gallon underground storage tanks for the collection of rainwater. This rainwater harvested is used for watering the plants inside the dome which is a great sustainable practice.

The replicated Namib Desert of southern Africa boasted of tall date palms and climbing among the pseudo cliffs were rock Hyraxes, klipspringers and the most darling meerkats like out of the movies. We literally ran past the Desert Caves which had 21 reptile species from Africa and Australia, including venomous snakes such as death adders, a cape cobra and the Inland taipan which is the world's second deadliest snake.

The Red Center of Australia is one of the world's most unique isolated deserts and we were lucky to see what it actually looks like here. Here, rock wallabies lived along with tall bottle brush trees and a tiny leaved Eucalyptus tree and some peccaries. A white Kookaburra sat unmoving, its thick beak pointed away from our curious gaze.

The Sonoran Desert, which is found in the southwest United States and northwest Mexico, is the world's second most biologically diverse desert. This area had ocelots watching us as we looked at them, and a bunch of peccaries, who did not care and wallowed in the desert dirt. We walked past bobcats, and then entered the hummingbird canyon where we encountered a waterfall in the parched desert. We particularly loved the Road runner exhibit made famous again by the cartoon character Road Runner and Cayote. Among the flat, prickly pear cactus and the tall endangered Saguaro cactus forest live tame quail, lizards and the occasional rabbit.

For me a rabid Rain Water Harvesting advocate, the thought that this massive structure with its hundreds of desert plants and animals was using rain water to sustain its needs, was indeed heart warming. I did see a lot of snow everywhere when I visited, which obviously also does translate into water and was sure that those tanks were filling rapidly, winter or no winter!

Three cheers for RWH :-)

Marianne de Nazareth

Water Water Everywhere or Nowhere?

“Nepal is the second richest country in the world in water resource”- sometimes this sentence seems to be a satire to the people and the system who are deprived of energy and moreover the availability of water. Thirsty Kathmandu is one of the worst scenario of it while if we take our binocular 520 km East away from Kathmandu, we will see another city –Dharan thirsty for water. Dharan Municipality is one of the 99 municipalities; located in Sunsari district within Koshi zone in Eastern Development Region of the country. Covering an area of 103.38 square kilometres, the municipality gives shelter to 27750 household (CBS, 2011). It has gained its identity as one of the cleanest municipalities in the country along with proper management of waste and other resources but not water.

Drained by 2 rivers, the municipality is rich in the surface water and it also receives rainfall intensity of 2.6m/year and rainfall of 2626 mm annually. Unable to supply adequate water to the city dwellers due to dependency upon surface water and ground water, the city is suffering from water scarcity throughout the year. Nepal Water Supply Corporation (NWSC) the only government body responsible for water supply to the city dwellers has been able to supply only 10.9 MLD (Dry Season)  and 13 MLD (Wet season) out of demanded 15.4 MLD. To supply the water NWSC abstracts water from Sardu Khola, and Khardu Khola while it also extracts groundwater from 3 deep boring. Remaining water is being supplied by the tanker suppliers meanwhile very few houses have adapted Rainwater Harvesting System (RWHS). It is a tragedy that despite of huge potentiality of RWH in the municipality NWSC has not aggressively promoted RWH in the municipality which could reduce the pressure on existing city supply.

Despite such shortage of water and municipalities effort to promote Rainwater Harvesting through leverage in building construction permission fees, very few houses are adapting RWH in their home. “People are not convinced that RW is drinkable hence they do not adapt RWH system,” says Mr. Suraj Shrestha- Senior Engineer at Dharan Municipality. However people are not aware of the quality of drinking water supplied by NWSC as a result the lab which should be maintained by NWSC does not function due to lack of concern from both government and the people.

The problem:

The main problem of promoting RWH harvesting is the perception on Rainwater Harvesting, as they are not assured with the quality of water however none of the people have ever tried to actually check the quality of rainwater. Moreover the municipality also faces difficulties in providing knowledge regarding RWH to the people due to lack of expertise within the municipality;  there are no organization working effectively in promotion of RWH. Meanwhile people having thatched roof has constructed the gutter system in their home but unfortunately the water is passed into the drainage in the city.

Likewise people get water supply up to 9 hours daily, hence people also not motivated in adapting RWHS. Meanwhile people are using same quality of water for all the household purposes ranging from drinking to flushing and gardening in most of the cases which is not waht a sustainale water manager would like to see. One of the most renowned organizations B.P. Koirala Institute of Health Science (BPKIHS) consumes about two hundred thousand litres of water daily for which they have separate source. But the story of using same quality of water for different purposes repeats here as well. The hospital has waste water treatment plant and treats its waste water but do not reuse which could at least be used for flushing toilets in hostel situated within the BPKIHS compound.

The Possibility:

Since Dharan receive substantial amount of rainfall (2.6m annually), there is high possibility of promoting rainwater harvesting. Meanwhile the general housing trend of Dharan shows that people have a small garden in front of their home which solves the problem of land for construction of storage tanks for RW.

Since Dharan Municipality though has provided leverage in tax while approving building construction if RWH is incorporated in their building plant people are not aware of adapting RWHS nor have they shown any concern, the municipality itself wants to make people aware and make them adapt RWH in their home. Hence the programs to promote RWH will surely be supported by the municipality. Also the municipality in collaboration with UN habitat is launching Green homes project of which RWN is a component, the project to launch RWH is likely to be supported and boosted by both the organizations.

Way Forward:

Dharan municipality has high potentiality for promotion and adaptation of Rainwater Harvesting system. This is attributed by the substantial amount of rainfall, already existing few components of RWHS such as gutters in most of the houses with thatched roof and availability of land for construction of storage of RW.  

Also people are mostly unaware of the sustainable use of water (more specifically reuse of water) that can help in managing available water and reducing pressure on the water supply system. If the people are made aware about the benefits of RWH and further regarding sustainable water management with practical demonstration, Rainwater harvesting may be adapted by the people.

Similarly since the main concern is the quality of water, re-establishing the lab of NWSC and checking water quality at the lab can help in assuring the quality of water and promoting RWH. Also collaboration with the municipality and UN habitat could give the positive results.

At present performing a detail study on the possibility of RWH in Dharan could be a crucial step. Likewise since the issue is also with the sustainable water management in various organizations a study on water management at BPKIHS and other institute is necessary along awareness and training programs. It is also a good idea to develop RWHS demonstration site in the public places and launch a pilot project in one of the ward of the municipality to promote RWHS.

Water is everywhere in Dharan but the tragedy is its not being tapped to its potential. It is definitely not a good idea to increase dependency upon the surface water and groundwater and waste substantial rainwater into the sewerage. Now it’s to the people whether they trap water for their use or just waste it!! It’s the perception of people and authority whether they see water everywhere or they perceive there is water nowhere!!!