It has been well recognised that water is a valuable resource and the quality of our water systems require sampling at a higher temporal and spatial frequency than is currently taking place. The AQUAWARN project aims to meet this challenge through the development of commercially competitive water quality monitoring devices. These will be capable of performing analytical measurements in situ - primarily aimed at freshwater and wastewater systems. The analytes of interest are mainly phosphate, nitrite, nitrate, and pH. The initial focus of this project is the assessment and optimisation of appropriate colorimetric chemistries for each sensing target. These chemistries have been developed and optimised using bench-top instrumentation. Integration within microfluidic chips followed to reduce the per sample costs. Microfluidic technology uses minute amounts of reagent per sample measurement, allowing for a dramatic increase in the number of potential assays per unit volume of reagent. Moreover, the integration of LEDs and photodiodes as light sources and detectors, coupled with syringe pumps, opens the way to new generations of low-cost, portable, and autonomous devices, capable of performing multiple in-situ measurements.  For example, an analysis requiring 50 uL of reagent implies 2,000 measurements are possible per 100 mL of reagent.