Hi Mr. Ali M Al-Fawzy

I'm not an expert in the water resources field, but I had some readings in that field as it's directly linked to my masters' study.

here are some papers for what I think is helpful

Kindly find the attached

Thanks

Sustainability means that water is used now without affecting the future generation. So in irrigation we need to use precision agriculture. In water supply we need to repair leakages and maintain the catchment by planting more trees.

many thanks to you mr. Kiprotich Kiptum

Hi, Mr Ali M Al-Fawzy you have posed a general question on the “Sustainability of water resources”, and may have many angles to look into.

Do we really know the meaning of “Sustainability” without giving the limits or boundaries for its applicability?

Considering both the time and intensity of water availability, before any interference from the human being, nature has adjusted itself to the yearly supply of water by the nature. The vegetation and the animal kingdom has developed, flourished and maintained themselves for centuries together. No significant problems are faced by the existing system during this period.

Now, we, the humans, want to utilise some part of the available water for our use. It may be domestic, industrial, agricultural use, etc or any other desired use. Naturally, for the “Sustainable” use of water resources, it is expected that even after a share of water resources is reserved or removed from the existing resources for this purpose, the existing system should not be affected. That will mean we store the “Additional” water available within a given area, for our use. The “Store” may be surface storage like Dam reservoir or underground storage in the soil. The desired yearly replenishment of water will be (assumed to be) taken care of by nature !

The assumption of most of the “sustainable water resources schemes” is on the above-mentioned lines.

The first question : What is the boundary area for such a scheme ? Maybe you see a surplus quantity available in a certain area, and try to use it as “Legitimate and scientific” quantity and utility of water. Nature is using this surplus water for the lower reach, where the locally available water is not sufficient. This lower reach utilises the extra water coming from the upstream. Thus nature is “Sustainable” for the water resource combined for these two regions together.

The second question : When or if your demand for water starts exceeding the present availability, then how do you manage it? One of the replies is that we bring it from some other resource, say the neighbouring area, or inter-basin transfers, etc. This or such solutions then lead us to the first question applicable to this “other resource”.

In the real sense, we look for our requirements, demands and needs against what is available in that region. Therefore the question, you have posed, may have to be rephrased to point to or to look towards a specific goal, purpose, etc.

Please see the attached Technical Paper explianing Sri Lankan Ancient Irrigation Technology which sustained more than 2000 years unlike modern approaches adapted during last century which sustained less than 100 years because of ecological issues. Efforts made to corect the mistake we did as modern water resource engineers are also explained

How Florida copied Sri Lankan ancient irrigation Village Tank approach as a strategy to capture local rain falls. They call it Disperse Water Management

https://www.sfwmd.gov/our-work/water-storage-strategies?fbclid=IwAR151iIuiAMJWZ16fTcMIhC-MeT9VwvE8xGUKq612y7SGN9n37G_jHc5nlo

You can see my articles on ReserachGate

1- Water management in Egypt for facing the future challenges

Article Water management in Egypt for facing the future challenges

2- Impacts of Climate Change on Water Balances at the Governorates Level in Egypt

Article Impacts of Climate Change on Water Balances at the Governora...

I would ask you what you mean? Sustainability, as a collection of sciences, spans effectively all of human understanding, with the possible exception of cosmology and xenobiology (and I'm willing to hear counter-arguments on them). I made a graphic one time that showed the various interconnections between how we use water, and who ends up thinking about it - from climate science through naval architects to farmers: it's a long list.

Sustainability is the capacity of the people of a community to meet all of their needs using the time and skills of their population, and the energy, resources, and ecological functions of the land/air/water that they are stewards of, in perpetuity. Looking at any component of that in complete isolation produces meaningless answers - sitting on a raft on Lake Superior will give you unlimited access to fresh water, but you'll die from a combination of starvation and hypothermia PDQ.

So, as part of a larger system, you need to both define the boundaries of what you mean, and understand the interconnections into the rest of the system. Groundwater resources, as an example? Storativity, transmissitivity, effective stress, recharge and discharge, but also fisheries, terrestrial ecosystems, flood storage, climatic effects, soil chemistry, etc, etc, etc. And then you have to add the human component, including long term demands, pre- and post- treatment, recreation, social values, etc...

In it's most trimmed down form, the Sustainability of water resources means the capacity of a surplus of water for human needs, without negatively impacting the ecological functions we utilize, in perpetuity. It is a capacity issue - how do you ensure water security in a manner that doesn't threaten the security of all of the other needs. In it's most expansive form, the sustainability of water is completely interconnected will everything else, including garbage in the oceans, water quality, changes in climate, cultural importance of water, population distributions, geopolitics and the causes of war, etc - I could write that list out for a week and still miss much of it.

So, what do you mean? How big is your question?

I have worked in this space. Will try to find some references.