I've always wondered how sensible is it to dig temporary holes/ditches that will store excess amounts of water and then later fill it back up once we're done with it. This is similar to how an empty swimming pool may be used to store excess rainfall. Perhaps the work put into it isn't worth the effort?
India's arid areas appear to have some experience with 'check dams' for precisely this purpose - turning monsoonal wet seasons into year-round wellwater.
Digging ditches is much less cost-effective for this purpose than building small dams, though they seem to have also worked with those, ditches filled with rocks under a cover and used as a storage tank.
It's very worth it. I can't find the link now, but there was a great article about traditional wier/retention pond building in Africa that both provided water but also helped recharge the local wells. The system had fallen into disrepair, and one local evangelized rebuilding the structures. It really took the entire community to rebuild and maintain, but improved the quality of life massively.
Meanwhile, Northern Europe has just seen one of the driest Octobers for a long while. Large areas has received less than five percent of normal precipitation. Stockholm has never had so little rain in October since measurements started back in 1786, beating a record from 1866.
Will be interesting to see if this continues into winter.
Meanwhile, greatest environmental disaster of this century is underway in Indonesia. 3 weeks more C02 has been released than annually in Germany & is currently releasing more C02 than the US economy. The flip side to this forecast in California. Heard of it?
