Bottom billion

Water and wastewater services engineering consultancy.

State-based development approaches are inefficient. Local governance mechanisms, including partnerships with small businesses (even informal ones), are essential for poverty reduction.

Maputo slum

40 years of expertise
Who are we?
We are a consulting firm, very experienced in the engineering of water and sanitation services. and sanitation services. For the past 40 years, our experts have travelled to countries in Africa, Asia and the Middle East Middle East to put their expertise at the service of vulnerable populations.
Our philosophy
We want to contribute to the fight against poverty by improving access to basic public services (water, sanitation, garbage collection, electricity) for the most disadvantaged populations. to basic public services (water, sanitation, garbage collection, electricity).

Bernard Collignon

Doctor in hydrogeology, Bernard Collignon has more than thirty years of experience in water supply projects in developing countries.

He worked successively for the Algerian government, for an NGO and as an independent expert, before creating the consulting firms Hydroconseil and Urbaconsulting.

He is a recognized expert in the modernization of public enterprises in the water sector and in the promotion of local SMEs, including those in the informal sector that play a central role in supplying marginal populations.

Fire hydrant and cart driver in Ouagadougou

completed projects
water supplies
of people
supplied with water
0 millions
African, Asian, Middle Eastern and Latin American countries

Water fountain in Nepal

Our jobs

Our projects

Our news

March 2023 - Hydrogeological study of the Jabal Sayid mine site in Saudi Arabia

Bottombillion finalized for SOFRECO the hydrogeological study of this mining prospect located in the middle of the desert. Several different techniques were combined (slug tests, logging, pumping tests, piezometric map, land tide monitoring...) in order to identify and characterize the groundwater resources (in quantity and quality).

February 2023 - Technical assistance to the municipality of Yatta (Palestine) for the modernization of its water service

Yatta is a secondary city in the West Bank (90,000 inhabitants), which escapes the Israeli occupation. Bottombillion was recruited by Hydroconseil to provide institutional and organizational expertise to the municipality, in support of the transformation of the municipal service into an autonomous water syndicate, which will encompass Yatta and neighboring municipalities. This technical assistance is financed by the Dutch Cooperation, through UNICEF.

January 2023 - Impact assessment of a new mining project on groundwater in Saudi Arabia

Bottombillion was recruited by SOFRECO to conduct hydrogeological investigations (watertable mapping, wireline logging, slug tests, pumping tests) for the Ghurrayyah mining project. The aim is to evaluate the water resources, the dewatering needs for the exploitation of a future mine and the potential risks for the environment

December 2022 - Groundwater for sustainable livehoods and equitable growth

The International Association of Hydrogeologists (IAH) has just published a synthesis book on the decisive contribution of groundwater to access to water for the world's poorest populations ( In this book, Bernard Collignon, Cédric Estienne and Ibrahim Nassour have written a chapter on the water supply of localities in the Lake Chad region thanks to shallow wells.

November 2022 - Definition study of the national development program for regional water companies (NSPIP)

Bottombillion was recruited by PWA (the Palestinian Ministry of Water) to define the implementation modalities of a national program to support municipalities in setting up regional water companies.

November 2022 - Teaching in the Master Edev (University of Montpellier 3)

Within the framework of the ADEV Master's program, Bernard Collignon has taught the "Cities and Metropolitization" course. These courses focus on the demand and supply of networked public services in slums.