The watershed is dead. Long live the multished!

By Patrick Keys

Summary: Watersheds delineated by topography and gravity are becoming obsolete. A new method of summarizing water supplies is needed. Enter the multished – defined as the surface, ground, and artificial water supplies for a particular location/region. 

Note: I borrowed the theme of this post’s title from these two papers: “Stationarity is Dead: Whither Water Management” by Milly et al. 2008 and “Stationarity is Dead: Long Live Transformation” by Craig, R.K., 2010.

Introducing the concept

The watershed is rapidly becoming out-dated as a useful boundary for water supply managers. For many regions, surface water flowing downhill has not encompassed the primary water supply for many years. Gravity is now supplemented by, for example, pumps for groundwater and reverse osmosis for seawater, to provide copious additional supplies.

This post aims to define this new mode of thinking as the multished. Why? Because assessments of water scarcity and water security are based on the availability of water supplies. If significant volumes of water are omitted from these assessments of water scarcity, then regions may be wrongly labeled as “water scarce” or “water insecure”. Future posts in this multished series will explore the specifics of how the multished framework could realistically influence transboundary water security.

Lets start with a working definition. The multished is the combination of surface, ground, and piped flows that provide water to a single location (e.g. nation, city, farm). The virtual watershed* and the precipitationshed** are both omitted from the multished for the reasons specified at the bottom of this post, however they may be included as the multished definition expands.

The multished is not appropriate for management of physical processes like flooding. However, the multished is appropriate as a tool for considering water availability for municipal, industrial, energy, or even agricultural irrigation water. More importantly, the multished is an important tool for reframing negotiations in perceived zero-sum situations.

This post will introduce this topic via a city with an interesting, and rapidly changing, multished (future posts will examine the actual numbers in greater detail).

Amman, Jordan (©Pat Keys 2011. All Rights Reserved)


Amman, Jordan: water poor or water rich?

Currently, Amman experiences chronic water shortages. Why? In short, it is a high-elevation desert city, with very little surface runoff, low rainfall, a booming population, and inefficient infrastructure. This lack of adequate supply forces periodic delivery, with water flowing from the tap often only twice a month.

Amman draws limited water supplies from the Zarqa river (which is part of the larger Jordan watershed). If you look at the surface watershed of Amman, it is very small, at 129 square kilometers (sq km):

Amman watershed (©Pat Keys 2011. All Rights Reserved)

Local surface runoff from the Zarqa river is virtually unmeasureable, because the channel has turned into a sewer. Amman does not survive because of its surface watershed; Amman survives because of its multished. If all of the supplies available to Amman are considered, the region supplying water looks something like this:

 Amman Multished 2012 (©Pat Keys 2011. All Rights Reserved)

And, by the year 2050, Amman’s multished could look like this…

Amman Multished 2050 (©Pat Keys 2011. All Rights Reserved)

Yes, really.

Let me explain.

1. Water flows south through the King Abdullah Canal (KAC), from the Yarmouk River (which forms much of the border between Jordan and Syria)

King Abdullah Canal, near Adasiyah Diversion, Jordan (©Pat Keys 2011. All Rights Reserved)

2. Water flows east from Israel, through the Beit Zera diversion, which is part of Israel’s National Water Carrier (NWC) network. It is likely that any water that flows through the Beit Zera diversion is of local origin such as from the Sea of Galilee. However, given the NWC can pump water in multiple directions, it is possible that water that flows in the North of Israel is actually desalinated sea water, or water pumped from the groundwater aquifers beneath the West Bank.

Beit Zera diversion, Israel(©Pat Keys 2011. All Rights Reserved)

And if planned construction proceed as follows…

3. Water will flow north through pipes that pump water out of the Disi Aquifer (in the South of Jordan).

Pipes for transporting Disi Aquifer waters north
(©Pat Keys 2011. All Rights Reserved)

4. If the planned Red Sea to Dead Sea Canal (aka the Red Dead Canal, or RDC) is constructed, the multished of Amman will extend south to the Red Sea.

Planned route of Red Sea Dead Sea conveyance

Multisheds re-frame the zero-sum game of water management

The water scarcity narrative is often riddled with the phrase “zero-sum”. Though some regions exist in a “zero-sum” reality meaning that there are no additional water resources available, many regions have access to much larger supplies of water. Amman, for example, has access to Israel’s growing desalinated water supplies via the Beit Zera diversion.
Of course, just because a pipe connects the two countries does not mean that they will share water, but it does mean that these options should be considered by water managers and diplomats as part of the negotiation terrain. The multished framework offers a new starting point for discussing water scarcity and water security. A negotiation based on Amman’s 2012 multished could yield very different outcomes from a negotiation based on Amman’s 2050 multished. Future posts on this blog will incorporate the multisheds framework into discussions of water security, to ensure that all water supplies that could be used, are in fact considered.

NEXT POST: A Multished Atlas  

The next post in this series will highlight key multisheds that are indicative of how water supplies are drastically being altered, including (for example) China’s North South diversion, Libya’s Great Manmade River, and the Colorado River.
* I omit virtual water because it cannot be used for the purposes liquid water is used, such as drinking, sanitation, cleaning, or irrigation purposes.
** The precipitationshed (as described by Keys et al., 2012) may be included in  future definitions of the multished, once it is clear how (if at all) human management can influence the transport of atmospheric moisture.

2 Replies to “The watershed is dead. Long live the multished!”

  1. Dear Mr. Keys
    Many thanks for sharing such an invaluable article and information about the diminishing status of the watershed management in Jordan.
    The article truly presents the scientific data and details of the changes that have happened over the years.
    In the founding days of my career in India, I worked extensively for the promotion of watershed development at the grassroots level in the rural reaches. We did not have such comprehensive scientific knowledge or data as you do since ours was just a start up nonprofit. However, that didn’t discourage us from our endeavours and we incorporated as much scientific details which were available around that time to us.
    I shall definitely share my experiences in my next blog post as your article has truly inspired me to write my next post about the state of watershed development in India.
    Keep up the good work of informing us!

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