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I'm curious, how do you define "area"? How long does water have to travel before its no longer in the "area"? How do you classify rivers? Water falls one pla

by sbov 8y ago

I'm curious, how do you define "area"? How long does water have to travel before its no longer in the "area"? How do you classify rivers? Water falls one place, and rivers direct it elsewhere, sometimes hundreds of miles away from where it first fell. Presumably these nearby rivers are still in area, even though the water flowing in them did not originate in area. For example, SF gets its water from a reservoir in the Sierras, 150 miles away. Much of California gets its water from just a couple places: the Colorado river (which runs along the border) and Northern California (and much of "Northern California" gets its water from More-Northern California). Some people who live in the southwestern deserts live closer to their water source than people in SF.

jameshart 8y ago
The relevant area is probably the watershed. In general, moving water between watersheds is hard, but within a watershed redistribution is possible. So total rainfall within a given watershed basically defines the water supply. http://digg.com/2016/river-basin-map-us http://digg.com/2016/river-basin-map-us
ethagknight 8y ago
Almost everywhere gets there water from some other area (even groundwater), which is why the concept of a “water supply chain” will come of importance. More specifically, “area” can be defined as the point sources for utility water distribution lines. As another poster mentioned, watershed is the common term. I’m not sure what point you are trying to make beyond water flowing downhill. My point was, if I’m a lender, and I’m about to lend to a property that has a history of water shortage + a severe threat of total drought, i’m hedging my bet by knocking back the appraisal to be sure I can get my money back from the property given the likelihood of drought. Likewise, I think there is an outsized chance wildfire or an empty fire hydrant, my premiums charged to the property are going way up. In these cases, “area” is looking at all possible options for getting potable water to the site for the foreseeable future, including high cost options like trucking supplies in to refill municipal water supplies.

by sbov 8y ago

jameshart 8y ago

The relevant area is probably the watershed. In general, moving water between watersheds is hard, but within a watershed redistribution is possible. So total rainfall within a given watershed basically defines the water supply. http://digg.com/2016/river-basin-map-us http://digg.com/2016/river-basin-map-us

ethagknight 8y ago

Almost everywhere gets there water from some other area (even groundwater), which is why the concept of a “water supply chain” will come of importance. More specifically, “area” can be defined as the point sources for utility water distribution lines. As another poster mentioned, watershed is the common term. I’m not sure what point you are trying to make beyond water flowing downhill. My point was, if I’m a lender, and I’m about to lend to a property that has a history of water shortage + a severe threat of total drought, i’m hedging my bet by knocking back the appraisal to be sure I can get my money back from the property given the likelihood of drought. Likewise, I think there is an outsized chance wildfire or an empty fire hydrant, my premiums charged to the property are going way up. In these cases, “area” is looking at all possible options for getting potable water to the site for the foreseeable future, including high cost options like trucking supplies in to refill municipal water supplies.