I saw a heartwarming tweet on Sunday. It was notable for two reasons. The first was that something heartwarming was a nice change of pace. But the second was that it spoke to a story that is currently very much in the news and also very relevant to my interests. The municipal water-service department in San Diego, California, is shipping the city of Calgary a spare section of pipe. It is apparently exactly what Calgary needs to help recover from the recent catastrophic water-main failure that has deprived the city of 60 per cent of its potable water supply, resulting in the declaration, this weekend, of a state of emergency.