Water Sensitive Cities

This week, KKL-JNF hosted a conference on the topic of storm water management in water sensitive cities. It was attended by the top experts in the field from Israel and Australia, along with KKL-JNF representatives from both countries.

April 7, 2011 15:30

KKL_070411_A. (photo credit: KKL)


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This week, KKL-JNF hosted a conference on the topic of storm water management in water sensitive cities. It was attended by the top experts in the field from Israel and Australia, along with KKL-JNF representatives from both countries.

The conference took place as part of KKL-JNF's ongoing activities in Israel and abroad to promote scientific research and development and to create international collaborations whose goal is information sharing, mutual learning and efforts to develop applied technologies and to assimilate them.At the present conference, which was held at the Maccabiah village in Ramat Gan, there were scientists from Monash University in Melbourne, Australia, the Technion, Tel Aviv University, Ben Gurion University and Israeli water experts.

One of the outstanding projects presented at the conference was the Kfar Saba biofilter – a project to purify urban runoff water and to reintroduce the water into the aquifer. The Hod Hasharon green wetlands project was also mentioned, at which effluents are purified by biological means and the clean water is used to help rehabilitate the Yarkon River. Both these projects were carried out thanks to contributions of friends of KKL-JNF in Australia.

The conference was led by Simone Szalmuk-Singer, Vic-president of JNF Victoria, Australia, who defined its goals: identifying the issues and common fields of interest in which scientists of both countries will be able to do quality work together. On KKL-JNF's achievements in this field she said: "We are proud to be part of an organization that brings scientists and researchers together to further common goals and forge a bond between Israel and Australia."

Yael Shealtieli, KKL-JNF CEO, also expressed pride that KKL-JNF is the host of such a qualitative collaboration: "I am certain that this collaboration will contribute to both Australia and also Israel. The ties with Monash University in Melbourne are very important. I would like to thank all the entities that are working on promoting new water technologies, for the benefit of Israel and her citizens.

"To date, KKL-JNF has built 220 water reservoirs and many purification plants throughout the country, so it is only natural that it should lead the way in developing new technologies for the management of urban water economies. We are creating a new study framework here, and it makes us very happy to know that so KKLmany experts chose to be involved."

Nicoli Maning-Campbell, the First Secretary of the Australian Embassy in Israel, drew a laugh from the audience when she said that one of the advantages of being a diplomat is that you have an opportunity to know a little about a lot of subjects, but not to know a lot about anything. She added that it is a well-known fact that Australia is one of the driest countries in the world, where droughts, fires and floods are part of everyday life.

She added: "In Australia, we are making efforts to reach a better balance between the water needs of the farmers and domestic usage. We purify sewage, recycle and harvest rainwater, among others. The lack of water affects the daily life of the citizens of Australia. It is clear that we must learn how to take better advantage of existent water sources, while trying to ensure present and future needs. Alternative water sources, that are not dependent only on rain, should be developed."

At the conclusion of her remarks, Maning-Campbell mentioned that she was aware that Israel has to face many water challenges, and she sees a lot of similarity between the two countries in this field. "We harbor no doubts that this collaboration will contribute to both sides. We hope for practical results from this meeting."

Central Water Challenges in Israel and Australia

After the opening remarks, the professional part of the conference began. The first session addressed the central water challenges that Israel and Australia face, and it included lectures by Professor Tony Wong of Monash University and Professor Uri Shamir of the Technion.

Professor Wong presented the challenges in the field of urban water in Australia and related to the similarity between Australia and Israel regarding the water issues faced by different cities in both countries. He noted that Australia had suffered from ten consecutive years of drought until this year: "The climate change that has been taking place and will be taking place in the future threatens our ability to provide water to most of the inhabitants of my country," Professor Wong said. In addition, the increase in the population means a lot of demand for water resources. "In the future, the cities will be even more densely populated, which will present new challenges. The question is, how can we foster awareness of the water crisis?"

According to Professor Wong, the challenge that Australia is facing is similar to the situation in Israel – ensuring water for a growing population, in spite of limited water resources, at a time of climate change and population growth. Professor Wong noted that we all take water for granted, because every time we open the faucet, we have it. "We need to understand the tremendous effort that is invested so we can have enough top quality water. A water sensitive city means that water management is critical for ensuring a survivable city."

Professor Wong enumerated three basic principles that need to be upheld, in order to support a water sensitive city:

1.    Harvesting water as a resource that needs to be protected.
2.    Cities that provide an ecosystem, so that the built-up environment supports the natural environment.
3.    Community awareness of the water crisis and existing technology, leading to the understanding that water must be saved and recycled. There is a need for professionals who will continue to ensure water resources, and authorities that encourage research and development.

Professor Wong and his colleagues at Monash University are involved in various projects, including harvesting and purifying rainwater, tracking climate changes and their influence on the water economy, creating a micro-climate, green infrastructures and reviewing government policy as regards creating alternative water sources.

Professor Uri Shamir of the Department of Environmental Engineering, Water and Agriculture at the Technion, spoke about the challenges and opportunities for water sensitive planning in Israel. He said that at the beginning of the 1990s, there began to be awareness of this issue, out of concern for the drop of the amount of water available in the underground aquifers and the lessening of water quality. The question of how it might be possible to build cities less damaging to the aquifers was raised.

According to Professor Shamir, runoff and drainage regulations are based on the assumption that this is harmful water: "There is a long way to go until people understand that we are actually talking about a valuable resource," said the professor. He noted that researchers at the Technion were involved in an attempt to change the existing approach to storm-water as part of Israel's master plan. Some of the emendations that were proposed were accepted by policy makers, but some were rejected, because a conservative approach fears the damage that might be caused by runoff water.

Professor Shamir said that the principles of water sensitive technology should be implemented at all levels of planning – on the national, municipal, neighborhood and domestic levels. In order to do so, there is an urgent need to train professionals who are active in this field, and there is a need for additional research papers that would monitor the management of water interfaces. One of the things the professionals would do would be to instruct residents how to store storm-water.

Another challenge, according to Professor Shamir, is changing the laws and regulations in order to allow the use of runoff and to recycle grey water legally. "The world around us is changing. In Israel, just like in Australia, people are beginning to understand that we must live in a way suitable for environmental conditions," he said. "As a result, politicians are getting 'greener', and entrepreneurs are also marketing to green communities."

Professor Shamir explained that there should be a national water management authority, which would include an administrative council for determining policy and allocations, a professional planning authority, and a mechanism that would review existing models. "The time has come to move from theoretical research, which has been conducted over the past twenty years, to field research, of which we have all too little." At the same time, he warned: "We must proceed with caution, because if we create pollution or flooding in new localities, we will only invite opposition that will stop progress in this field."

Water Sensitive City (WSC)

The second session was devoted to the topic of water sensitive cities. Professor Ana Deletic of the Center for Water Sensitive Cities at Monash University said that cities should be seen as centers for harvesting runoff: "This water is in close proximity to exactly where we need it – our cities - and it is not of inferior quality. It is preferable to take advantage of it, also because otherwise, it pollutes the oceans."

According to Professor Deletic, it is possible to plan facilities for harvesting, treating, storing and channeling the water in open spaces in urban regions. Water purification by means of plants makes the surroundings more beautiful and greener, and at the same time, contributes to the water economy: "There are different ways to treat runoff water. We are focusing on the biofilter, because we have one here in Israel. Another possibility, for example, is storing water for toilets in an underground container, which is a much smaller facility than the biofilter."

Professor Deletic added that the challenge in taking advantage of runoff is the ability to store it and purify it from the pollutants it gathers from the street: "During the rainy season, water is collected, and it can be used during the dry season," she explained. The advantage of the biofilter is that it conserves natural water sources, prevents flooding, improves the urban micro-climate, is an alternative water source, saves drinking water, beautifies the city, and is relatively inexpensive. "The resistance to assimilating this technology must be overcome," Professor Deletic said, "and the local experts are the people who can lead this move."

Together with the university team, Yaron Zinger, an Israeli doctoral student from Monash University, developed Israel's first biofilter, which was built in Kfar Saba, with the help of friends of KKL-JNF from Australia, in cooperation with the Kfar Saba municipality. "Our goal is to prove that this idea works, in order to lead to a change in the regulations and to make it possible to build similar facilities throughout Israel."

Every year, about 200 million cubic meters of polluted runoff water are absorbed by the sewage system and channeled to the sea, which is a waste of huge amounts of precious water and also pollutes natural water reservoirs. The biolfilter system is a method of storing urban runoff water and treating it by means of a filtering system and special types of plants and bacteria that are very efficient in treating pollutants. The purified water is reintroduced into the aquifer for urban use.

According to Zinger, tests that were done until now show that the water that infiltrates the Kfar Saba system is extremely polluted, while the water that comes out of the biofilter is almost potable, according to most parameters. Signs of improvement in the groundwater can already be seem, and researchers continue to follow progress. "We are about to prove the concept," Zinger said, "but we need additional pilot projects in different sorts of regions. KKL-JNF is currently leading the move to build more biofilters in Israel." 

Tami Shor of the Israel Water Authority spoke about Israel's water crisis and ways of dealing with it. "We must take action to increase sources of water, by purification, recycling and better use of natural resources. At the same time, we need to lower the demand for water be increasing awareness and increasing the price of water." According to Shor, one of the major changes that took place over past years has been passing water corporations law, and transferring responsibility for municipal management of the water economy to corporations rather than the municipal authority itself.

"The goal is to provide service for the residents, efficient management and to make certain that income from selling water is invested in the field," Shor said. There are currently 60 water corporations that are active in 130 local authorities in Israel, which covers most of Israel's residents. "The corporations have improved the situation, but there's still a lot of work to do," she said.

The Water Authority uses the price of water as a tool to create balance. "We need to ensure the economic feasibility of producing water by digging wells and drilling. On the other hand, if water is too cheap, demand will increase along with water usage. The balance is such that the more water that is pumped from the will, profitability drops, in order to guarantee that the well can be used in the future, but not to encourage greater consumption."

Producing water during the winter is not economic, and it is cheaper to buy water. The goal is to ensure the use of recycled water, not to pump new water. "We hope that within a few years, it will be possible to set suitable regulations whose goal will be to make advanced treatment of water possible," Shor concluded.

Professor Avital Gazit of the Faculty of Life Sciences at Tel Aviv University told the audience that he participated in an international conference of UNESCO, where there were 63 lectures on the subject of managing water interfaces, but none of them were relevant to Israel. "One has to be very careful about reaching conclusions about one region from another region. This is why this meeting is so important, because it's a meeting of experts who work together with us and consider solutions appropriate for Israel. This is also the unique importance of the biofilter that was built in Kfar Saba."

According to Professor Gazit, using rainwater and runoff water in cities is very KKLdesirable in terms of ecology, economics and also socially. "Even when it's not economically feasible, it is critical for a healthy environment and healthy society," he added.

Professor Gazit described the preferred conditions for harvesting runoff – even distribution of rainfall over the year and continuous rainfall all during the day. The Middle Eastern climate is characterized by a short, wet winter and a long, dry, hot summer. Most of the precipitation comes during short, intensive storms, during which there is a lot of rainfall. "These circumstances need to be taken into account when planning facilities for treating rainwater," Professor Gazit emphasized. "Is it possible to skip the research and to go straight to implementation? There is a need to determine where it is possible to begin implementation and where more research is necessary. It's not clear as to the relevancy of experience gained in other places for Israel."

Proferssor Gazit asked a number of questions about the biofilter: A strong storm brings a lot of very concentrated pollutants, and it needs to be ascertained whether the system is capable of dealing with them, including survival of the plants. On the other hand, what happens to the system after a long dry period? How is the fear of vandalism dealt with? Who funds the maintenance of the facility? If we want to channel water to a stream, the water must be stored and channeled in the summer, not during the winter when the stream is full of water. What can be done if there is no suitable place for storing the water?

Professor Eran Friedler of the Technion related to the level of pollution on major expressways. These roads are extremely polluted with oil, gas, tires, air pollution and more. Pollution includes heavy metals, oil, gas, organic and inorganic materials. He presented a model based on data whose purpose is to predict the concentration of pollutants on expressways. This model takes the variables that affect the level of pollution into consideration, including the amount of traffic, rain and wind. It was found that the dry period after the last rain and the amount of daily traffic have the greatest influence on the pollution level. The influence of the different variables is not linear. As part of the study, algorithms and formulas were developed with the aim of building a model that can predict the level of pollution.

Professor Evyatar Erell, an architect from Ben Gurion University, lectured on the role of vegetation in planning a micro-climate in dry cities. He claimed that rain dispersion in Israel is not conducive for urban vegetation, due to the long dry period. The conclusion is that irrigation might be necessary in some areas.

On the topic of "green roofs", a question was asked: "Are roofs planted with flora suitable for the Middle East, and is the cooling effect they have significant?" He answered that according to the research that he conducted; the degree of energy utilization was not significant in relation to the amounts of water that evaporate. The contribution of low vegetation is not significant, while higher plants create shade and may contribute to cooling. "A green roof needs irrigation. The question arises as to whether it's justified in a country where water is a precious commodity. It might be simpler to install some sort of insulation that doesn't need to be irrigated," Professor Erell said.

Another study examined the cooling effect of various gardens in Sde Boker. In one of the gardens, trees provided shade, in a second one, a shade-providing net was installed, and in the third, grass was planted. The results were that the garden with trees was cooler than the garden without trees. The trees were found to be more efficient than the netting. At night, there is almost no difference between the gardens. The significant difference is during the afternoon. The combination of shade and lawns created the most comfortable micro-climate during the hot hours of the day. The main difference had to do with shade and prevention of heat radiation from the exposed ground.

"When the contribution in relation to water is measured," Professor Erell explained, "obviously grass needs a lot more water than trees, so trees and lawns together do, in fact, have the greatest effect, but they also use a large amount of water." In conclusion, he said that the recommendation of this study is to use vegetation carefully, particularly in hot areas, where shade is very significant. Of course trees contribute to other fields that were not the subject of this study.

In a conversation at the end of the day, Joe Krycer, CEO, JNF Victoria, Australia, said that in the past, KKL-JNF concentrated on fundraising and strengthening ties with the community in Israel. Over the past few years, however, activities have expanded to collaborations on water, quality of life and the environment.

"Experts from Australia and from Israel visit each other in order to share research and for joint study, and the present conference is an additional example of this," Krycer said. "The fact that we are facing similar challenges in the field of water creates an opportunity for fruitful cooperation between Israel and Australia."
After the lectures, a number of the conference participants went for a visit to the Kfar Saba biofilter, where they saw the facility they had heard about in the lecture hall. Yaron Zinger led the visit to the site. Robert Schneider, CEO, JNF Australia and Grahame Leonard, Federal President JNF Australia also joined the group

Zinger explained to his audience that Kfar Saba has a particularly high percentage of pollutants in its groundwater, and three nearby wells were obstructed by the pollution. At the biofilter, water is harvested during the winter, and then treated and reintroduced to the groundwater. In the summer, when there is no rain, the biofilter treats the polluted water that is pumped from the wells.

The water is filtered by passing through a network of platforms and vegetation. The upper level remains unsaturated, and therefore primarily supports aerobic processes. The lower levels have a low concentration of oxygen. The system is efficient in distancing suspended solids, heavy metals, nitrates (nitrogen and phosphorous), and oils. After the biological treatment, water quality tests are made. A well that is 87 meters deep and another, wider well that is 24 meters deep are used to enable the water to infiltrate into the aquifer.

The visit to the aquifer concluded the first day of the conference. The next day was devoted to formulating a research proposal on making Israel's cities water sensitive, presenting the plan to all the conference participants, and a discussion on the proposal.

For Articles, comments or use please contact
Ahuva Bar-Lev
KKL-JNF – Information and Publications
Email: ahuvab@kkl.org.il
Phone: 972-2-6583354 Fax:972-2-6583493


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