National household-cistern program delivered by community networks — Semiarido, Northeast Brazil

Location

Semiarido, Northeast Brazil-9.0000, -40.0000

Description

The Programa Um Milhao de Cisternas (P1MC) has been building standardized 16,000 litre roof-catchment cisterns for families across the Brazilian Semiarido since 2003, delivered by the ASA network of about 3,000 civil-society organizations, with cisterns built by locally trained masons and family labor. By 2022 the program had built 1,146,210 cisterns.

Health impacts are peer-reviewed and large: a 73 percent reduction in diarrhea risk, Giardia prevalence of 4.8 percent versus 16.7 percent in children with versus without cisterns, and improved food security. The program received the UNEP Future Policy Gold Award in 2017.

The program's fragility is fiscal: annual construction collapsed from 149,098 cisterns in 2014 to 5,946 in 2022 under federal budget cuts, and was partially revived after 2023. Current cost is about R$5,000 to 6,000 per cistern.

Outcome recorded as success: over a million households gained a dry-season drinking water asset with independently documented health gains, while the funding collapse stands as a warning that delivery capacity evaporates when the federal budget line does.

Metrics

5

Cisterns built by 20221,146,210cisterns

Diarrhea risk reduction (peer-reviewed)73percent

Giardia prevalence in children, with vs without cisterns16.7 percent (without)4.8 percent (with)

Annual construction pace under budget cuts149,098 (2014)5,946 (2022)cisterns/yr

Current cost per cisternapprox. R$5,000 to 6,000BRL

Funding

Brazilian federal funding channeled through the ASA civil-society network; current cost approx. R$5,000 to 6,000 per cistern

Lessons learned

A single standardized design plus locally trained masons plus family labor let a civil-society network build over a million cisterns with consistent quality.
Health gains are among the best-documented of any community water program: 73 percent diarrhea risk reduction and a three-fold lower Giardia prevalence in children.
Delivery through about 3,000 local organizations reached dispersed rural households no utility network would serve.
Fiscal dependence is the structural weakness: construction fell from 149,098 cisterns per year to 5,946 when federal budgets were cut, then partially recovered after 2023.
Household cisterns solve drinking and cooking water; productive water needs complementary programs.

Sources

3

Documented Jul 24, 2026

Arnaud Gissinger