Nature-based solutions - Sustainable water management

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WASH - Water, Sanitation, and Hygiene for developing countries

WASH (or Watsan, WaSH) is an acronym that stands for "water, sanitation and hygiene". Universal, affordable and sustainable access to WASH is a key public health issue within international development and is the focus of Sustainable Development Goal 6. In 2015 the World Health Organization (WHO) estimated that "1 in 3 people, or 2.4 billion, are still without sanitation facilities" while 663 million people still lack access to safe and clean drinking water. In 2017, this estimate changed to 2.3 billion people without sanitation facilities and 844 million people without access to safe and clean drinking water (Source: Wikipedia).

Sustainable Sanitation (SUSAN) techniques are a valuable response to WASH challenge; a number of SUSAN techniques are available, from simple solutions aiming to improve hygienic conditions (such as biobags) to more hygienically safe way to manages faces, up to more classical solutions such as sewer and wastewater treatment plant proper for developing countries.

IRIDRA contribute to WASH challenge, collaborating with NGOs and development programs for developing countries, designing low-tech wastewater treatment plants (such as constructed wetlands or lagoons), or helping in the organization of WASH plans. IRIDRA gathered experience in several developing countries (such as India, Honduras, Haiti, Palestine, Vietnam, Tanzania, Sri Lanka) and is able to propose and design SUSAN solutions proper for different needs. IRIDRA was also part of the NaWaTech project, which aimed to develop an integrated approach of sustainable water management in India. Moreover, IRIDRA is a partner of the Sustainable Sanitation Alliance (SuSanA).

SUSAN Techniques


 peepoo 1  web

 peepoo 2  web

Biobag use steps



arborloo 1

arborloo 2

Examples of crops growth with Arbolo: pumpkin Ethiopia (on the left) and tomatoes in Zimbabwe (on the right)


Safe pit latrine emptying

latrine emptying  web

Different trucks for pit latrine emptying



composting  web

Example of barrel transport for composting


Compost toilet

 compost toilet 1  web

 compost toilet 2  web

Compost toilet in a house in Puerto Morelos (Mexico)


Public biogas toilets

public toilet  biogas digester  web

 Two examples of public toilets in Kenia with an anaerobic digester and biogas production; the toilets are also equipped with urine diversion and rainwater harvesting systems


Public toilets with septic tanks

public toilet  septic tank


Urine diversion toilet - UD - Urine diversion dry toilet - UDDT

ud  web

Example of urine diversion toilets


Rainwater harvesting

rainwater harvesting  web

Two rainwater tank in Sri Lanka


Dry detention basin

dry detention basin web

Example of dry detention system for flood mitigation


Retention pond

retention pond  web

Example of retention ponds for flood mitigation


Green wall for greywater treatment

living walls  web

Example of a green wall in Botswana


Constructed wetland for wastewater treatment and reuse

cw  web

Example of a constructed wetland WWTP serving a small settlement in Tanzania


SDRB - sludge drying reed bed

sdrb web

Example of SDRB at different application scales


IRIDRA's experience


grigie riuso palestina oxfam  web

Separation, treatment with a constructed wetland, and reuse of greywater from a Beduin village in Palestine. The treated greywater is reused for irrigation of olive trees and fodder. The nature-based solution was designed by IRIDRA, commissioned by the NGO OXFAM Italy, and funded by EU ECHO, FAO, and Sardinia Region


grigie riuso pune web

Separation, treatment with a constructed wetland, and reuse of greywater from the Campus of the College of Engineering in Pune (India). Designed by IRIDRA as a case study of the NaWaTech project.


industriali vietnam web

Constructed wetland system for the treatment of wastewater produced by a fish industry in Yen Hung (Vietnam), designed by IRIDRA.


urbani sarra  web

Constructed wetland for treatment of wastewater of Sarra village, Nablus (Palestina), serving 4300 inhabitants. The project aimed to improve the sanitary condition of the village and to reuse the treated wastewater for irrigation of olive trees. Designed by IRIDRA and funded by the European Union.