11

Turning to the Sea for Drinking Water

第十一章

向海洋索取饮用水

Throughout history, cities have employed a similar set of approaches for obtaining drinking water. Those urban dwellers lucky enough to live near ariver or lake have usually focused on making their local surface water safe to drink. If there is an adequate groundwater supply underneath the city, people who lack easy access to surface water have obtained their drinking water from wells. And after a city’s population had grown to a point where the local waterre sources no longer suffice, canals and aqueducts have been built to importwater from increasing distant regions.

纵观历史，各个城市为了获得饮用水都采用了一套相似的方法。那些有幸生活在河流或湖泊附近的城市居民，通常会集中精力保证当地的地表水可以安全饮用。如果这个城市有足够地下水的话，获取地表水不方便的居民还可以从水井获得饮用水。当一个城市人口数量增长，以致当地的水资源难以满足其需求时，人们就会修建运河和引水渠，把水从遥远的地方输送进城。

By the end of the 20^th century, many cities had become so populous that their drinking water needs could no longer be met easily by the normal sources. Initially, water-stressed cities adopted the Three R’s of reduce, reuse, and recycle to maximize their limited water resources. That strategy worked for a while, but depending on the city’s size and location, as well asthe enthusiasm of its residents for low-flow shower heads and recycled water, the costs often reached a point where further water savings became difficult. Rather than raising people’s water rates to encourage conservation or accepting the idea that water availability might limit their size, cities have increasingly looked to the sea as a means of breaking free of the water cycle. After all, two-thirds of the world’s big cities are located along a coast.¹ If water-stressed coastal cities can find a cost-effective technology for removingthe salts from seawater, they will no longer have to wait for the sun and wind to send their drinking water to them by way of the water cycle.

到２０世纪末，许多城市已经人满为患，人们对饮用水的需求已经难以再通过这些常用方法得到满足。起初，缺水的城市采用了“减少、再利用和再循环”的“３Ｒ”原则，使有限的水资源得到最大的利用。这一策略在一段时间内曾取得一定的效果，但它的发挥过于依赖城市的规模和位置，以及当地居民对低流量淋浴喷头和循环水的积极性。节水达到一个点后，要进一步节水就十分困难。尽管如此，这些城市并没有用提高水费去鼓励人们节约用水，或者接受城市发展受制于用水的命运，而是逐步把大海视为摆脱对水循环依赖的一种方式。毕竟，世界上三分之二的大城市都位于沿海地区^［１］。如果用水紧张的沿海城市可以找到一种经济高效的去除海水中盐分的技术，他们将再也不需要等待太阳和风通过水循环的方式为他们送去饮用水了。

(Last paragraph of Chapter 11)

Despite the setbacks encountered in Tampa and Carlsbad, more proposals for coastal desalination plants are moving ahead in California and Florida. From the trials and tribulations of the pioneering projects, it is evident that desalination may be part of Water 4.0, but it is not a panacea for the clean water challenges of America’s coastal cities. With each new project it becomes easier to separate the reality of seawater desalination from the rhetoric onboth sides. Seawater desalination is a mature, reliable technology. But if countries or regions are unable to adopt a centralized planning model similarto Israel’s, and if they continue to insist on green power, carbon offsets, and lengthy environmental impact reviews, seawater desalination will remain expensive relative to other options for the foreseeable future.

虽然海水淡化厂在坦帕和卡尔斯巴德遇到挫折，但更多的沿海海水淡化厂建厂计划正在加州和佛罗里达州推进。从这个前沿性项目的尝试和挫折来看，很显然，淡化水可能为“水４．０”的一部分，但它不是解决美国沿海城市的清洁水所面临困难的灵丹妙药。随着每一个项目的推进，海水淡化的现实将更容易从双方的争执中显露其真面貌。海水淡化是一个成熟可靠的技术。但如果一个国家或地区无法采用类似于以色列的那种集权式的规划模式，如果他们继续坚持绿色能源、碳补偿和冗长的环境影响评价报告，那么相对于其他获取淡水的方式而言，近期内走海水淡化之路仍将会是一个昂贵的选择。

ps. I typed up the English myself, so errors are possible.

水４．０：饮用水的过去、现在与未来

［美］戴维·塞德拉克　著

徐向荣　等译    虞左俊　校

上海科学技术出版社

出版时间：2015.08

ISBN：978-7-5478-2729-1

定价：38元

Water 4.0: The Past, Present, and Future of the World's Most Vital Resource

Paperback：March 31, 2015

by David Sedlak (Author)