Everything on the site

01 · High Plains

• 01.1The water under Kansas fell as rain before anybody farmed itMuch of the High Plains aquifer holds water recharged during and since the last glaciation, which is why drawing it down is not a cycle but a subtraction.
• 01.2How far the water has fallen, county by countyThe decline is not uniform: some counties have lost most of their saturated thickness and others almost none, and the map of that is the real story.
• 01.3The wells that measure it, and who reads themThe record exists because somebody drives out to a monitoring well and drops a tape down it, year after year.
• 01.4What grows on water that will not come backThe cropping pattern above an aquifer is a decision about how fast to spend it.

02 · Subsidence

• 02.1Jakarta, several metres downPumping groundwater from beneath a coastal city compacts the sediment and the surface drops, which is a different problem from sea level rising.
• 02.2Mexico City's drains run uphill nowUneven subsidence across a former lake bed has changed the gradients the drainage was designed around.
• 02.3Why the ground does not come back upCompaction of fine sediments is largely permanent, so the lost storage is lost even if the water returns.
• 02.4Measuring a sinking citySatellite radar interferometry maps millimetres of movement across a whole city, which is how the extent became undeniable.

03 · Rivers

• 03.1The Colorado, divided in a wet decadeThe allocation was written when the river was running unusually high, and every argument since has been about arithmetic done at the wrong moment.
• 03.2Every claimant and the share on paperThe paper entitlements add up to more than the river has carried in most years since the agreement was signed.
• 03.3Lake Mead's bathtub ring as a legal instrumentThe pale band on the rock is a water level, and water levels trigger clauses — which makes a stain on a cliff a legal event.
• 03.4The delta, and the water sent to itThe river has not reliably reached the sea for decades, and the small deliberate releases since are measured experiments.

04 · Engineering

• 04.1Desalination and the brine that comes with itReverse osmosis works and is expensive in energy, and it produces a concentrated stream that has to go somewhere.
• 04.2Reuse, and who will drink itTreated wastewater can be made cleaner than most sources; the obstacle has rarely been the engineering.
• 04.3Drip irrigation's real arithmeticEfficiency at the field can increase total consumption at the basin, because the water that used to return underground no longer does.
• 04.4The cheapest water there isLeakage repair and metering deliver more water per unit of money than any new source, and neither photographs well.