Around the world, water rights systems govern the allocation of water to a multitude of users. Such systems primarily come into play during times of drought, when some users have to be shorted. Yet their management during times of excess can have implications for subsequent drought impacts. This is evident in the State of Colorado, where under “free river conditions” in which there is sufficient water to satisfy all water rights, anyone—including individuals lacking water rights—can divert as much as they want, unconstrained by the limit of their water right. Here, we estimate the amount of excess water used under such conditions within Division five of the Upper Colorado River Basin in the State of Colorado. Comparing the daily water withdrawals of diversion structures along the Colorado River and its tributaries with their (daily) water rights, we find that in 2017, 339 structures report days with excess withdrawals, amounting to 108 million cubic meters (87,577 acer feet). While such excess withdrawal is legal in Colorado, we argue that the free river condition is an antiquated rule that will make much needed reform of water allocation within the water-stressed Colorado River Basin more difficult. We offer policy suggestions to address it.

中文翻译：

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堵住水权制度的漏洞以节约用水：科罗拉多河流域


在世界各地，水权制度管理着向众多用户分配水的情况。此类系统主要在干旱时期发挥作用，此时某些用户必须短路。然而，在过量时期对其进行管理可能会对随后的干旱影响产生影响。这在科罗拉多州很明显，在“自由河流条件”下，有足够的水来满足所有水权，任何人——包括缺乏水权的个人——都可以随心所欲地转移，不受其用水权限制的限制。水对了。在这里，我们估算了科罗拉多州上科罗拉多河流域第五区在这种条件下的过量用水量。将科罗拉多河及其支流沿线引水建筑物的每日取水量与其（每日）水权进行比较，我们发现，2017年，有339个建筑物报告超额取水天数，总计1.08亿立方米（87,577宏英尺）。虽然这种超额取水在科罗拉多州是合法的，但我们认为，自由河流条件是一项过时的规则，将使缺水的科罗拉多河流域内急需的水分配改革变得更加困难。我们提供政策建议来解决这个问题。