Dear Peter, That sounds like ...

Dear Peter,

That sounds like a very interesting and useful project! I would be very cautious about attributing too many changes in the hydrological cycle to “climate change”, as both occur continuously. Dealing with them appropriately is important, but be wary of weighting a discussion or relevance to ambiguous or multiply-defined concepts.

Changes in rainfall and water levels occur worldwide at different times, conditions and rates. Some last a season or two, others may endure for years. Rarely has any particular condition remained stable, and even the definition of “stable” can be misconstrued without taking into consideration the direct impact of increased usage of the resource!

I think that it is most important to understand and develop plans that mitigate potential changes in the reliability and quality of water sources. Those include flooding as well as drought, and the distribution and types of usage as well as the recycling of the used water back into the hydrological cycle and water systems.

In my own community (rural) in the Philippines we had a rather severe water table level decline last year, affecting all public and private wells in the Province. Both the individual (in my case) and goverment (in the community) response was to re-work most of the wells to clean them out and deepen them – close to the limit of most of the “shallow well” pumping systems. That now remains in place, but the annual rainfall and water replenishment has not really fallen off considerably, so the water availability situation is now back to a previous normal state. However, exacerbating the water level problem and remaining a threat in the future is the continued development of communities displacing older farms and creating a larger continual demand on the area water aquifers.

As with many communities worldwide (possible worse in “First-World” countries) there is often no distinction between supplies for potable water and general usage. Thus, a high demand for potable water is wasted on uses that do not require that purity, and which can often be sourced from places other than the potable water aquifer. Rain collection, rivers, and reuse of “gray water” are all areas that are under-utilized.

On the other side of climate variations, severe storms (typhoons, here) can not only cause direct damage from flooding, but the flooding usually has the potential to contaminate normal sources of potable water. Mitigating flooding effects is a separate concern for the most part, but it must include considerations of impact to water storage, distribution, and processesing facilities as well as implications for home sanitation requirements.

I hope that this gives you some background on our activities with water source fluctuations, if not specifically a “case study” of a particular intervention.

Best regards,

Steven Cooke, MchE, FAIC

President, Process Systems Consulting.