Files The preservation of natural areas has a long tradition in Kyoto. The first measures for the preservation of natural areas in and around the city begun in 1930 with the designation of the Scenic Landscape Districts. This first measure considered mainly the natural areas located at the limits of the city near the surrounding mountains and some patches of green areas within the urban fabric. All the protected green areas were related to places of historic importance as palaces or temples, as the Kiyomizudera located in the Eastern mountains (Bureau, 2016). Among the few protected green areas of Kyoto that were not associated with built heritage were the banks of Kamo River, the main river of Kyoto that has been for long one the city´s most popular public areas.

The extraordinary growth of the city after World War 2 put under test Kyoto´s preservation measures, but a number of new policies helped confront the situation. In 1964, what began as a dispute over the conservation of the forests of Kamakura city near Tokyo -the Oyatsu Dispute-ended in the Ancient Capitals Preservation Law of 1966, which provided Kyoto's municipality with more legal tools to protect the historic landscapes from the growing urbanization (Asano, 1999).

Preservation measures could not always be applied efficiently, and because of the pressure of land development they needed constant updates. In the following years, several amendments and new policies were created to improve the protection legislation, as, among others, the Act on Urban Green Space Conservation (created in 1973 to be valid in all Kansai region) created to protect suburban greenery, the Kyoto City Ordinance on Conservation of Natural Landscape (enacted in 1995) to protect the view of the mountain ranges from the city, and special regulations for specific areas as the Riverside Aesthetic Landscape District (2005) made to control the development the areas near the margins of urban and suburban rivers.

Although today the preservation of urban natures makes emphasis on sustainability and on the benefits of nature for the citizens, the protection of Kyoto's urban natures has been traditionally related to cultural and aesthetic interests. It is for that reason that one of the most important conservation tools was, and still is, the protection of views (or vistas). The protection of urban and natural views is certainly not unique to Kyoto or Japan. Vancouver for example has protected view cones to guard the mountain landscape as appreciated from the city, while in London, protected views corridors were established since the 1930s to protect the views of important landmarks as the St. Paul's Cathedral (Karaga, 2015). In Kyoto, there are thirty-eight officially recognized vistas under the Vistaed View Creation Ordinance (all of which include natural features) that were selected out of 597 options taken from literature and citizens choices (Bureau, 2007). Despite the predominantly aesthetic emphasis of this approach, the city's rivers and its waterfronts have nonetheless greatly benefited from these measures that have protected the green areas along the main urban rivers. The new ordinance includes the category of Views from Waterfronts, which includes the Hori River, the Uji River, and the Lake Biwa Canal Sluice, as well as the 'pleasant views' of the Kamo River from its Bridges (Bureau, 2007).

In Japan, the protection of views is associated with the traditional gardening design concept of borrowed landscape or shakkei (Taylor, 2006). When applying this concept, the distant natural background is used in combination with the nearer features of the landscape to create the illusion of continuity. Unlike the protection of the landscape as the object to be appreciated, shakkei focuses in the interaction of the different layers of the landscape. In Kyoto, the intrusion of unwanted objects in borrowed landscapes is considered a major loss, as in the case of the garden of the Entsu-ji Temple, which is said to be now ruined by the construction of housing buildings that interrupt the illusion of a continuous nature. To prevent this from happening elsewhere, there are strict height restrictions in the areas surrounding buildings of historical importance, as the Kamigamo Shrine in the North of the city and in the traditional district of Gion near the city center (Figure 1). At several points along the Kamo River for example, the protected views have helped maintain the illusion of a surrounding nature that hides the city behind the greenery (Figure 2).

Due to the abundance of natural values in Kyoto and its close relation to built heritage, the preservation policies of the city are in close agreement with the Historic Urban Landscape, which as defined by the UNESCO, is the resulting landscape of the historic layering of cultural and natural values and attributes. In the 2011 recommendations for Historic Urban Landscapes, the UNESCO suggested that heritage conservation should be integrating into the broader management goals of the city, including sustainability. Preserving existing resources is an essential part of sustainability, and therefore, the conservation of natural and built heritage is now considered a necessary task of sustainable urban management.

But the relation between sustainability and heritage is not restricted to the preservation of resources. The compatibility of traditional practices and sustainability is a well-recognized fact in practices as varied as food production or architecture [(Parham, 2017); (Moor, 2017)], and this agreement has also proven to be manifest in urban planning. In the case of Kyoto, a good example in this respect are the measures taken in the historic Togetsukyo Bridge, that crosses the Katsura River in the protected area of Arashiyama. The current bridge was built in 1934, before the enforcement of laws promoting the use of lighting equipment, and therefore lights in the bridge were banned once the bridge reached the heritage status. However, after long negotiations, the installation of lighting on the historic bridge was finally accepted after proposing a sustainable solution that included a small hydraulic power generator powered by the flow of Katsura River (National Small-hydro Council (Zenkoku ko suiryoku riyō suishin kyōgi-kai). “Arashiyama Hydroelectric Power Victory”, n.d.). The installation began in 2005, and it became the first micro-hydropower system to be installed in one of the major rivers of Japan, illustrating the promising potential for the application of environmentally friendly strategies in historical areas.

On the other hand, the increasing environmental awareness has also led to the modification of some of Kyoto´s traditions, as in the case of the practice of 'Yuzen Nagashi'. This old tradition was the final stage of the dyeing process of fabrics, in which silk stripes were placed along the rivers of Kyoto to clear them of excessive glue and dye, creating the effect of a multi-coloured water. In the 1940s, because of the growing concerns with water pollution, this practice was gradually discouraged until it was eliminated under the Water Pollution Control Law of 1974 (Database, 2010). Today, a modified version of this practice is recreated for special festivals during the summer, using non-polluting colorful fabrics placed along some of the rivers and canals of the city.

Since the protection Kyoto's rivers and their environments has been driven mainly by their association to historical heritage and aesthetic values, the waterways that have received more attention over the years have been the Kamo River and its margins, the Takano River in the North of the city, the Shirakawa River, particularly the section that runs along the historic protected area of Gion, and the Lake Biwa Canal. However, for most of the 20^th century, minor rivers and streams without an apparent scenic value that could justify its protection have disappeared or deteriorated.

For example, the Horikawa canal, which once had a tremendous importance for the activities of the West of the city, once it lost it original functions it was gradually covered in most of its course and, as a measure of flood prevention, its water source was cut soon after the Second World War. It was not until 1985 that a group of citizens formed the Horikawa beautification group to try to restore some of its former aesthetic qualities. After years of negotiations, a restoration plan was presented in 1995, and the canal that had been buried and dried for fifty five years was brought to new life with a plan that combines flood prevention, amenity, and recovered heritage (Bureau, 2010)(Figure 3 and Figure 4). This change of attitude towards urban watercourses is the reflection of a worldwide trend of renewed environmental awareness that leads contemporary citizens to increase the demands for the improvement of the natural infrastructure of cities, which is helping to build a more diversified approach to the management of urban natures.

Besides the protections of rivers through the preservation of the natural urban landscapes, national and regional legislation for the management of rivers. However, the goal of these legal measures has traditionally been the control of floods, which is a priority of Kyoto’s municipality. Historically, floods have cause great damage to the city and its surrounding, specially along the courses of the Kamo, the Katsura, and the Uji Rivers, where many historic protected areas are located (Figure 5 and Figure 6). Measures against floods started as early as the 9th century, but the changing conditions of factors affecting the flow of rivers, as the construction of dams, forestation or the surrounding mountains, and weather conditions, keep testing the improvements made in flood prevention. For example, the heavier rains occurring during the last years have caused serious problems since the infrastructure was not fit to bear the new precipitation levels. During the typhoon Man-yi of 2013, more rain fell in one day than in the average of the month (Masaki & Kei, 2015), prompting the flood of the Hozu-Katsura River in the historic area of Arashiyama, and causing considerable harm to the area. In 2018, the effects of the Typhoon Prapiroon forced the evacuation of hundreds of Kyoto citizens living near the major rivers while the currents wrecked the city´s riparian infrastructure. Improved flood prevention measures have greatly improved safety, and, since the risk of flood is cannot be completely eradicated because of the mutable nature of rivers, policies are focus on reducing flood damage (Waley, 2000).

Although flood prevention is still one of the main priorities of national and regional river administration, the approach of the River Law amended in 1997, has added water use and river environment protection as equally important purposes of river administration (Ikeuchi & Kanao, 2003). The full ecological potential of urban rivers is being explored and exploited only recently. A previous measure from 1990 from the Ministry of Land, Infrastructure, Transport and Tourism established a policy called Nature Oriented River Works, and with the amendment of the River Law this measure took new force and nowadays is slowly reaching urban rivers minor urban streams.

In addition to the increasing attention paid to river environment quality in legal measures and official administration, contemporary awareness on environmental issues has led to a growing influence of the Japanese preservation movements, which are now reaching urban grounds. Traditionally, the efforts of environmental activists manly targeted the wild and hard-to-find nature, located as a rule in areas distant from urban centers (Asano, 2007). However, the interest in smaller ecosystems, as the ones that might exists within cities, is gradually increasing. The interest in the creation and preservation natural areas within urban contexts is broadening the approach to the management of water environments, expanding the initial safety and aesthetic concerns into a more systemic view that considers its ecological aspects. Until recently, the way in which the manmade natural riverbanks were conceived tended to be uni-layered, focusing mainly in visual aspects, and therefore created meagre environments for biodiversity. Today it is understood that the natural areas along urban rivers can be managed as 'bio-highways' (Taylor & Findlay, 2006), since they are the most propitious areas within urban environments to promote rich and complex ecosystems.

It has to be noted that, when it comes to Japanese urban watercourses, the categories of man made and original natures are extremely blurred. As pointed out before, Kyoto’s rivers have been tamed since its foundation in the 8^th century for purposes of irrigation, transportation, or flood protection, and countless canals have been created, rearranged, and removed. Within the contemporary Landscape Plan of the city of Kyoto, the Riverside category of the Aesthetic Landscape Districts includes mainly engineered rivers and man-made canals as the Takase River, a transportation canal dug in the 17th century, or the famous Biwa Lake Canal, which was designated as Modernization Heritage in 2007 because of its importance for the history of Kyoto. The urbanized riversides of these canals might contrast with some sections of the landscaped margins of the Kamo River designed to look natural, but it has to be considered that both of these contexts are equally planned and deliberately crafted (Figure 7 and Figure 8).

The category of historic urban landscape includes built heritage as well as natural heritage in its border sense (without considering the level of human intervention), but when dealing with environmental issues the distinction between of original and modified nature (as in a natural stream or a designed canal) becomes more complicated because of the association with the debates on which natures should be preserved and how (Baldwin et al., 1994).

Without attempting to address the ethical or philosophical implications of the debates regarding original and modified environments, some basic facts of nature within urban contexts need to be clarified. First, what is generally classified as natural in urban planning differs from the definitions used in environmental discussions dealing with wilderness, and considerations about original states of nature or rewilding approaches are not always suitable for the urban contexts. Urban natures refer for the most part to areas where the majority of the integrating elements are living natural features, category which includes from relatively untamed urban forests to the most cultured versions of nature as parks or gardens. Secondly, the action of preserving or creating natural environments within cities has usually a different purpose than the protection of nature in areas uninhabited by humans. Within urban contexts, the role of nature as an amenity usually takes priority over the concerns on ecosystems, which is a relatively new concept that is only beginning to be included in the discussions of urban nature.

The expansion of the approach to river protection in Kyoto is being achieved through the integration of the civil society into the management process, while also considering the local history and traditions, measures which are also in line with the suggestions of UNESCO for the preservation of Historic Urban Landscapes from 2011. Within Japanese urban planning, the national and regional governments were traditionally seen as mere managers of infrastructure (Sorensen & Funk, 2007), without real engagement with the improvement of the urban quality of life. According the Japanese scholar Shun-Ichi J. (Watanabe, 2007), a new urban environmental administration with a bottom-up style of planning is currently growing in Japan thanks to the Machi-zukuri movements (which literally translates as City Making). These civic associations grew out of the combination of the traditional neighborhood associations and the environmental movements of the 1960s and 1970s that confronted government strategies that favored economic growth over quality of life. Since the collapse of the bubble economy in the 1990s, there have been important political readjustments, and local groups have been increasingly involved in the governance of urban space (Sorensen & Funk, 2007).

The current River Improvement Policy of the city of Kyoto has integrated the concept of River making (Kawazukuri) and Waterfront making (Mizube-zukuri) into its measures to manage the city’s watercourses. In Japan, these concepts have been applied since 1990s as pilot projects promoted by the Ministry of Construction´s River Bureau to approach the re-landscaping or rivers with natural materials, minimizing when possible the use of concrete, which was for many decades the predominant material used to in the river interventions (Waley, 2000). The idea behind the integration of civil movements with municipal activities in the particular case of Kyoto is to complement the complex tasks of flood prevention, which need to be carried out by the government, with other responsibilities that can be executed by citizens and local businesses, as landscaping, cleaning, and maintenance of riversides (Bureau, 2012). With the integration of River making programs, smaller rivers of areas that were not considered significant from the perspective of Kyoto’s official history are being renovated with a systemic approach. Many of these projects are part of an effort to merge existing watercourses and flood control, but contrary to the infrastructural projects of the previous decades, current developments consider the cultural and ecological context, as well as the aesthetic factor. Some examples of these projects are the improvements of the Arizu River, or the Nanase River, where a layered project placed the flood prevention measures underground liberating the surface to create a landscaped park (made by Tanaka Survey and Design Office, Figure 9 and Figure 10).

A significant aspect emphasized in the River Improvement Policy is the importance of recognizing the history and cultural meanings associated with the water course. The policy points out that the original scenery of the river and its margins should be considered in the renovation projects (Bureau, 2012). It has to be noted that in the case of Kyoto, as elsewhere in Japan, references to the original state of the river as in its natural state or to the way the river environment was before human intervention, are not as common as references to the condition of the river before the late 19th century modernization. Many renovation and relandscaping projects in Kyoto and other cities place educational images of past epochs (mainly Edo period) showing the local traditions, industries, and activities that took place in and around urban rivers.

The new approach recognizes the social relevance of watercourses of all sizes, acknowledging that rivers are an integral part of the material fabric of the city, and of Kyoto’s local cultures. In the new policy, it is argued that the loss of contact with the water has caused the loss of the common wisdom on how to control flooding and manage watercourses, and the improvement plans include measures to restore the familiarity of the society with the rivers, a concept called shinsui, that even considers the consciousness to ‘fear’ water (Bureau, 2012). Many restoration projects are using the concept of shinsui park, and create designs that allow the public to approach and interact with the water instead of creating an environment that only allows to see the watercourse from the distance, and also include many features of traditional Japanese gardens as waterfalls, bridges, and the creation of little islands (Waley, 2000). Although there are some critics of this landscaping concept in Japan, shinsui parks in Kyoto, as the one designed for the renovation of Horikawa canal, have proven to be extremely popular, particularly for children.

River making associations come in many shapes and administration styles (Kusakabe, 2013). The participation of civil societies in city planning is not always easy, and there is it is concern that the alleged participation could be reduce to a mere supply of information on the official plans. Still, the involvement of non-governmental entities as the Kyoto Environmental Activities Association (KEAA) that promotes the public interest in the environment, the volunteer groups that clean the riverfronts, or the association of Kyoto Hotaru (fireflies) dedicated to study of these popular insects, has propitiated a more comprehensive approach to the urban river management.

Although environmental concerns have entered the legal framework of river management relatively recently, Kyoto’s interest on the preservation of the natural values of the city, particularly the interest on landscapes and vistas, have aided the protection of the city´s watercourses and its environments. Unfortunately, the emphasis placed on historic relevance and aesthetic values to determine the landscapes to preserve led to the neglect and deterioration of most secondary streams and canals of the city, dedicating all the protection efforts to a few privileged examples as the Kamo River or the Biwa Canal. There is still much room for improvement, however, recognizing the historical and cultural dimension of the natural and engineered urban streams, even when they have no touristic value, has helped Kyoto’s municipality to improve the urban landscape while generating new and valuable ecosystems.

The contemporary awareness on the importance of the protection of the environment by citizens and officials, have made sustainability a concept as valued as tradition in the management of Kyoto's heritage, as shown in the case of the Togetsukyo bridge where new sustainable solutions coexists with age-old heritage. At the same time, this new consciousness of the importance of the environment has created a new sensibility towards nature that led to the reexamination of past solutions for flood control, and the concrete casements of urban streams are gradually being remodeled into landscaped urban parks.

The current tendency in Kyoto's management of rivers is to create fine grained policies, each one adapted to the local characteristics and circumstances. Despite the skepticism about the real power gained by civil society in the decision-making process of urban planning, the advantages of sharing efforts have been so far a positive experience. The evolution of the protection and management of Kyoto's urban rivers reflects the changing attitudes of society towards the natural environment. Civil movements and researchers are addressing countless dimensions of the complex environment of urban rivers —as the influence of sound and light pollution, or the user’s interactions with the local flora and fauna— that could further enrich current practices. The citizen’s interest in environmental issues, together with the public acceptance of sustainable measures as a suitable complement of traditional settings has potential that is worthy of exploration.

This research is part of a larger investigation in Kyoto's waterways supported by Japan Foundation