Rainwater harvesting: Way ahead to encash the alternative water resource

Depending on the agroclimatic region the strategy may be different but the idea is the same — catch water where it falls

By Mahreen Matto
Published: Monday 13 May 2019
Representational Photo: Getty Images

Around the world, cities are facing huge water-related risks that are aggravated by climate change, rapid urbanisation and outdated infrastructure resulting in flooding, water scarcity and rehabilitation costs on a scale that overwhelm the capacities of cities.

However, at times, cities or regions are geographically well placed in terms of their resources, but due to existing water management practices, which include enormous concretisation in the name of urbanisation, our cities suffer.

Take the example of Rwanda, a sovereign (and landlocked) country in central Africa with a varied geography covering roughly 25,000 square kilometre of land and 1,400 sq km of water. Rwanda receives average annual precipitation of 1,200 millimetre (mm), and the rainfall ranges from as low as 800 mm in Eastern Province to about 2,000 mm in high altitude of north and west. Thus, there is ample scope to practice rainwater harvesting (RWH).

Looking at the urban trend, the country has one of the highest population densities in Africa (483 people/sq km). As per the 2012 census, Rwanda had approximately 12 million citizens and an annual population growth of 2.6 per cent. Around 19.4 per cent of the total inhabitants live in urban areas.

Its capital, Kigali, is a major urban centre with 76 per cent of the population categorised as “urban”. At the same time, Rwanda is also among the countries having the lowest per capita water availability (670 cubic metres per capita per year) and storage capacity in Africa. Besides inadequate per-capita availability, floods accompanied with soil erosion are a common issue in the country.

Considering the current scenario, RWH must be promoted as part of infrastructure development to achieve water augmentation and stormwater management. At national level, provisions like VISION 2020, Economic Development and Poverty Reduction Strategy highlight rainwater as the most feasible option for providing alternative source of water. Still, RWH is not considered as an immediate response to the issue of water stress in the country.

A recent report by New Delhi-based non-profit Centre for Science and Environment (CSE), submitted to Rwanda Water and Forestry Authority (RWFA), assesses the applicability of RWH as one of the potential measures to achieve sustainable water management in urban areas of Rwanda.

Through the report, an attempt is made to understand and scale up RWH by accessing the existing framework and practices involved in implementing RWH in the city of Kigali. The report focuses on high visibility and high impact urban RWH interventions or case studies at various levels like schools, neighbourhoods, hotels, and industries.

The case studies have been viewed on various parameters such as the type of RWH structure (storage or recharge), socio-economic and environmental impacts, and water supply scenario.

The key challenges found were divided into various categories:

Legal and institutional framework

  • No status report or data available to showcase the enforcement of law to implement RWH
  • Lack of coordination between state and nonstate stakeholders
  • Majorly RWH systems are implemented by individual users/owners
  • Technical knowhow of RWH structures and technologies is minimal

Social aspect

  • Documentation of best management practices of RWH systems is absent
  • Lack of research on importance and use of RWH for non-potable purposes in Rwanda
  • Negligible community involvement/engagement for implementing RWH systems
  • Resistance among people to use harvested rainwater as an alternate source of water

Infrastructural aspect

  • Availability of funds is a concern in practising RWH
  • No alternative provision for water supply augmentation
  • Lack of adequate storm water management infrastructures

After analysing the challenges with regard to scaling up RWH in Kigali, a roadmap was developed defining the strategies required, in a holistic and sustainable manner. What came out clear is that in order to have a buy-in for RWH, legal and institutional framework, social and environmental aspects should be considered and worked on.

Strong leadership and coordination among state and non-state stakeholders would be necessary for a successful wide-ranging RWH implementation project. In addition, a coordinated educational programme will have to be conducted to dispel myths about stored water and to create the required skills base.

The statutes and bylaws regarding water would also have to be reviewed to avoid legal impediments. The multi-layer institutional model requires substantial initial investment and effective communication between organisations, water users and governments should be looked into.

An approach like RWH isn’t just a viable alternative to current practices, it also aligns with the 2030 Sustainable Development Goals, which include clean water, sanitation and sustainable cities, with community involvement.

The need of the hour is to go back to the use of traditional approach and adopt sustainable, cost effective, low maintenance practices. Depending on the agroclimatic region the strategy may be different but the idea is the same — catch water where it falls.

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