#6 Research meetup: NeatWork - 15 years of analytics for gravity-driven water systems

In this meet-up, led by Jean-Philippe Vial (Geneva, Switzerland), we looked at how NeatWork combines optimisation and simulation to design water-distribution systems that operate without pumps or manually controlled regulators. The tool has been used routinely for 15 years by Agua Para La Vida in Nicaragua and can be operated by technicians without supervision from qualified engineers.

Why do rural water systems need a different design approach?

For rural communities with limited resources, water systems need to be affordable to operate and straightforward to maintain.

NeatWork focuses on systems that run using gravity alone, avoiding powered pumps and manually operated regulators. At the same time, the network needs to regulate itself so that water flows remain reliable even when independent users draw water intermittently and unpredictably.

Why is this an optimisation problem?

The underlying problem is to identify a low-cost network design while accounting for uncertainty in how people will use the system.

Mathematically, this can be formulated as two-stage stochastic optimisation: a method for making an initial design decision while considering many possible future patterns of water use. Evaluating those designs also requires calculating water flows through a system of nonlinear equations.

Because solving the complete mathematical problem directly would be too complex for the intended application, NeatWork uses a more practical two-part approach.

How does NeatWork work?

A first module uses a heuristic — a practical method for finding a good solution without exhaustively checking every possibility — to generate possible network designs.

A second module then simulates those designs across large numbers of realistic water-use patterns to test whether the resulting flows remain suitable.

This keeps the analytical complexity in the software rather than transferring it to the people using the tool.

How has the tool been used in practice?

This meet-up looked at how NeatWork has been used routinely for the past 15 years by Agua Para La Vida (APLV), a non-governmental organisation operating in Nicaragua.

Despite the complexity of the optimisation and simulation behind it, the tool can be used routinely by technicians without supervision from qualified engineers.

The work was developed jointly with Frédéric Babonneau, Gilles Corcos and Laurent Drouet.