{"id":21142,"date":"2023-04-04T13:45:43","date_gmt":"2023-04-04T12:45:43","guid":{"rendered":"https:\/\/www.vtei.cz\/2023\/04\/planovane-revitalizace-vodnich-ekosystemu-v-praze-4\/"},"modified":"2024-08-19T17:53:26","modified_gmt":"2024-08-19T16:53:26","slug":"planovane-revitalizace-vodnich-ekosystemu-v-praze-4","status":"publish","type":"post","link":"https:\/\/www.vtei.cz\/en\/2023\/04\/planovane-revitalizace-vodnich-ekosystemu-v-praze-4\/","title":{"rendered":"Planned restoration of aquatic ecosystems in Prague 4"},"content":{"rendered":"

Prague 4 district in\u00a0accordance with the\u00a0National Action Plan for\u00a0Adaptation to\u00a0Climate Change [1], Concept for\u00a0Protection\u00a0from the\u00a0Effects of\u00a0Drought of\u00a0the\u00a0Czech Republic [2], Strategy for\u00a0Adaptation\u00a0of\u00a0the\u00a0Capital City of\u00a0Prague to\u00a0Climate Change [3] and Methodology for\u00a0Rainwater Management in\u00a0the\u00a0City [4, 5], similarly to\u00a0other progressive-minded parts of\u00a0Prague, is\u00a0preparing investment actions to\u00a0support and strengthen green-blue infrastructure in\u00a0the\u00a0city. One of\u00a0the\u00a0most visible measures with truly demonstrable effects on\u00a0the\u00a0support of\u00a0biodiversity and water retention\u00a0in\u00a0the\u00a0landscape is\u00a0the\u00a0restoration\u00a0of\u00a0aquatic ecosystems. In\u00a0the\u00a0case of\u00a0the\u00a0capital city of\u00a0Prague and its most populous district of\u00a0Prague 4, these are mainly the\u00a0restoration\u00a0of\u00a0canalized (straightened or\u00a0piped) streams, or\u00a0desilting, strengthening or\u00a0comprehensive restoration\u00a0of\u00a0ponds and small water reservoirs in\u00a0a\u00a0highly urbanized landscape. A\u00a0specific area is\u00a0newly emerging bodies of\u00a0water in\u00a0places where water naturally tends to\u00a0be retained after longer periods of\u00a0rainfall and the\u00a0area thus cannot be used for\u00a0any other purpose, or\u00a0even in\u00a0places where there was\u00a0no body of\u00a0water before (although here in\u00a0the\u00a0narrower sense of\u00a0the\u00a0word it is\u00a0not restoration). For\u00a0such areas\u00a0created by\u00a0human intervention\u00a0in\u00a0order to\u00a0strengthen the\u00a0diversity of\u00a0aquatic and wetland vegetation, the\u00a0name artificial aquatic biotope has\u00a0been adopted. Let us have a\u00a0look at the\u00a0differences and specific pitfalls of\u00a0individual restoration\u00a0using three specific examples.<\/span><\/p>\n

CONSTRUCTION OF THE BRAN\u00cdK AQUATIC BIOTOPE<\/h2>\n

The\u00a0idea of\u00a0an aquatic biotope in\u00a0Za Ml\u00fdnem street in\u00a0Prague\u2019s Bran\u00edk district arose from the\u00a0initiative of\u00a0the\u00a0councillor\u00a0for\u00a0the\u00a0environment of\u00a0Prague 4 district, based on\u00a0an example of\u00a0good practice from Prague\u2019s Lysolaje district, where a\u00a0similar cold-water biotope was\u00a0put into\u00a0operation\u00a0in\u00a02017 (Fig.\u00a01<\/span>). It was\u00a0created by\u00a0rebuilding the\u00a0already non-functioning fire reservoir on\u00a0the\u00a0Lysolajsk\u00fd stream under the\u00a0so-called \u201cMiraculous spring\u201d (Z\u00e1zra\u010dn\u00e1 stud\u00e1nka) under Housle natural monument, which with a\u00a0yield of\u00a03.5 l\/s is\u00a0one of\u00a0the\u00a0strongest springs in\u00a0Prague. In\u00a0contrast to\u00a0the\u00a0Lysolaje natural source of\u00a0water for\u00a0the\u00a0biotope, only two solutions were possible in\u00a0the\u00a0anthropogenically raised floodplain\u00a0of\u00a0the\u00a0artificially deepened Kunratick\u00fd stream (Fig. 2<\/span>): supply the\u00a0future biotope with a\u00a0channel\/pipeline directly from the\u00a0stream, or\u00a0its own water source (well). Due to\u00a0the\u00a0highly variable water quality of\u00a0Kunratick\u00fd stream, which is\u00a0affected by\u00a0overflows from storm water overflow higher up in\u00a0the\u00a0basin, it was\u00a0decided to\u00a0build an 8 m deep well and to\u00a0pump groundwater from the\u00a0floodplain\u00a0under the\u00a0Bran\u00edk structural slope.<\/span><\/p>\n

The\u00a0biotope on\u00a0the\u00a0artificially lowered terrace will have a\u00a0free water area of\u00a0240 m2<\/span> with an average depth of\u00a0145 cm, and the\u00a0maximum depth of\u00a0180\u00a0cm (Fig. 3<\/span>). The\u00a0lake basin\u00a0will be divided into\u00a0a\u00a0deep-water and a\u00a0littoral zone for\u00a0planting aquatic and wetland vegetation\u00a0(Fig. 4<\/span>). The\u00a0estimated groundwater abstraction\u00a0will be 0.3 l\/s, with the\u00a0possibility of\u00a0its strengthening and regulation\u00a0with regard to\u00a0the\u00a0seasons and maintaining the\u00a0positive water balance of\u00a0the\u00a0biotope. The\u00a0overflow will be handled via a\u00a0classic monk sluice with a\u00a0short, shallow bed with stone steps opening into\u00a0Kunratick\u00fd stream. The\u00a0inflow of\u00a0water from the\u00a0well to\u00a0the\u00a0biotope is\u00a0planned on\u00a0the\u00a0surface through a\u00a0system of\u00a0flat stones in\u00a0order to\u00a0ensure the\u00a0sound effect of\u00a0running water. Considering the\u00a0size and depth of\u00a0the\u00a0biotope, a\u00a0year-round low water temperature of\u00a0up to\u00a016 \u00b0C can be expected.<\/span><\/p>\n

The\u00a0biotope should gradually become a\u00a0refuge for\u00a0psychrophilic species (amphibians, invertebrates), and the\u00a0natural biocorridor\u00a0of\u00a0Kunratick\u00fd stream should function\u00a0as\u00a0a\u00a0source of\u00a0these organisms. The\u00a0aquatic biotope will not be intended for\u00a0swimming; in\u00a0addition\u00a0to\u00a0its ecological function\u00a0it will serveas\u00a0part of\u00a0the\u00a0mini educational trail and for\u00a0educational purposes in\u00a0the\u00a0topic of\u00a0adaptation\u00a0measures of\u00a0the\u00a0capital city of\u00a0Prague. The\u00a0immediate surroundings, including the\u00a0park furniture, will be appropriately landscaped so that the\u00a0biotope becomes a\u00a0natural part of\u00a0Za Ml\u00fdnem park.<\/span><\/p>\n

The\u00a0total cost of\u00a0building the\u00a0biotope, including subsequent vegetation\u00a0adjustments, will reach around 8 million\u00a0CZK; running costs (regular cleaning, pump drive, fees for\u00a0groundwater abstraction) will be paid from the\u00a0operating budget of\u00a0the\u00a0Prague 4 Municipal Council. Completion\u00a0of\u00a0the\u00a0biotope is\u00a0planned for\u00a0May of\u00a0this\u00a0year. More information\u00a0about the\u00a0project can be found on\u00a0the\u00a0PinCity website [6].<\/span><\/p>\n

\"\"<\/a><\/span>Fig. 1. Aquatic biotope in\u00a0Prague\u2018s Lysolaje<\/h6>\n
\"\"<\/a>Fig. 2. Site for\u00a0Bran\u00edk aquatic biotope in\u00a0Za Ml\u00fdnem park (view to\u00a0the\u00a0east)<\/h6>\n
\"\"<\/a>Fig. 3. Visualization\u00a0of\u00a0Bran\u00edk aquatic biotope (view from the\u00a0same place as\u00a0in\u00a0Fig. 2<\/span>)<\/h6>\n
\"\"<\/a>Fig. 4. Status of earthworks as of 1. March 2023 (view to the east, in the foreground is\u00a0the\u00a0future lake basin\u00a0with an already established monk sluice)<\/h6>\n

RESTORATION OF KUNRATICK\u00dd STREAM<\/h2>\n

Kunratick\u00fd stream is\u00a0a\u00a0right-hand tributary of\u00a0the\u00a0Vltava, flowing through Bran\u00edk in\u00a0its lower reaches and creating a\u00a0valley through which the\u00a0southern link (Ji\u017en\u00ed spojka) from Barrandovsk\u00fd bridge leads to\u00a0north-south motorway (Severoji\u017en\u00ed magistr\u00e1la). In\u00a0its entire lower section, from Kunratick\u00fd forest to\u00a0the\u00a0confluence with the\u00a0Vltava, Kunratick\u00fd stream is\u00a0heavily improved and channelized. The\u00a0water draining into\u00a0the\u00a0straightened narrow, partlially concrete channel does not interact with the\u00a0groundwater level for\u00a0most of\u00a0the\u00a0year (Fig. 5<\/span>), which causes very small flows in\u00a0the\u00a0dry season. In\u00a02017, the\u00a0Department of\u00a0Environmental Protection\u00a0of\u00a0the\u00a0City of\u00a0Prague decided to\u00a0restore part of\u00a0the\u00a0lower section\u00a0(approx. 650 m) of\u00a0Kunratick\u00fd stream gradually in\u00a0several stages, taking into\u00a0account its length. The\u00a0first of\u00a0the\u00a0three parts above Vrbova street was\u00a0supposed to\u00a0be implemented in\u00a02021; however, in\u00a0view of\u00a0the\u00a0re-opening of\u00a0the\u00a0construction\u00a0procedure due to\u00a0the\u00a0concurrent Bran\u00edk biotope project, implementation\u00a0with an expected investment of\u00a025\u201330 million\u00a0CZK was\u00a0postponed until 2024 at the\u00a0earliest. In\u00a0the\u00a0meantime, at least part of\u00a0the\u00a0so-called zero phase took place below Vrbova street, consisting of\u00a0a\u00a0change in\u00a0the\u00a0material and structure of\u00a0the\u00a0banks and bottom of\u00a0the\u00a0riverbed (Fig. 6<\/span>), which significantly increased diversification\u00a0of\u00a0the\u00a0riverbed, reduced of\u00a0water flow velocity and increased the\u00a0clarifying (self-cleaning) ability of\u00a0the\u00a0stream. This\u00a0year, the\u00a0second part of\u00a0the\u00a0zero phase of\u00a0restoration\u00a0of\u00a0the\u00a0stream should take place in\u00a0a\u00a0similar way, up to\u00a0its piping below Mod\u0159ansk\u00e1 street.<\/span><\/p>\n

As\u00a0part of\u00a0the\u00a0above-mentioned first phase, on\u00a0the\u00a0other hand, overall restoration\u00a0of\u00a0the\u00a0stream will be started, including the\u00a0anthropogenically raised river floodplain\u00a0of\u00a0the\u00a0right bank (Fig. 7<\/span>), which will be artificially lowered, widened and slope conditions adjusted in\u00a0such a\u00a0way as\u00a0to\u00a0allow not only future public access to\u00a0the\u00a0water, but also creating a\u00a0floodplain\u00a0(Fig. 8<\/span>). Contact with the\u00a0groundwater level will become possible in\u00a0the\u00a0channel made from loose granite blocks, the\u00a0roughness will be increased, and water outflow velocity will be reduced; together with a\u00a0smaller artificial pool, this\u00a0will create a\u00a0suitable refuge for\u00a0new species of\u00a0aquatic fauna, for\u00a0which the\u00a0existing channel with fast water outflow is\u00a0unsuitable (Fig. 5<\/span>). Due to\u00a0the\u00a0limited space given by\u00a0the\u00a0complex ownership structure of\u00a0the\u00a0land on\u00a0the\u00a0banks of\u00a0the\u00a0stream, more generous meandering of\u00a0the\u00a0riverbed will not be possible, only slight undulation. The\u00a0newly created floodplain\u00a0and riverbed will be supplemented with dead wood from trees growing today high above the\u00a0stream bed. As\u00a0part of\u00a0the\u00a0third phase, a\u00a0short section\u00a0of\u00a0riverbed and floodplain\u00a0between the\u00a0existing riverbed and the\u00a0emerging Bran\u00edk biotope will be restored in\u00a0a\u00a0similar way, so that both structures interact and a\u00a0synergistic effect is\u00a0achieved [7].<\/span><\/p>\n

\"\"<\/a>Fig. 5. Anthropogenically straightened lower part of Kunratick\u00fd stream in Bran\u00edk<\/h6>\n
\"\"<\/a>Fig. 6. Restored part of\u00a0Kunratick\u00fd stream below Vrbova street<\/h6>\n
\"\"<\/a>Fig. 7. Anthropogenically raised floodplain in Za Ml\u00fdnem park with an artificially incised Kunratick\u00fd stream bed intended for restoration (view to the west)<\/h6>\n
\"\"<\/a>Fig. 8. Visualization of the restored part of the stream and the river floodplain (1st phase, view from the same place as in Fig. 7<\/span>)<\/h6>\n

RESTORATION OF THE WATER BODY IN\u00a0JEZERKA PARK<\/h2>\n

The\u00a0vision\u00a0of\u00a0the\u00a0restoration\u00a0of\u00a0Jezerka Park in\u00a0Nusle was\u00a0presented in\u00a0a\u00a0landscape study [8], which emerged from a\u00a0competition\u00a0of\u00a0three architectural proposals, developed on\u00a0the\u00a0basis\u00a0of\u00a0extensive participation\u00a0with the\u00a0public. Due\u00a0to\u00a0the\u00a0size of\u00a0the\u00a0park, restoration\u00a0will take place in\u00a0several stages; the\u00a0first stage will involve the\u00a0restoration\u00a0of\u00a0the\u00a0dried water body (\u201clake\u201d) and its immediate surroundings, including the\u00a0restoration\u00a0of\u00a0the\u00a0small watercourse above it, flowing from the\u00a0drainage below the\u00a0Na Jezerce theatre (Fig. 9<\/span>).<\/span><\/p>\n

The\u00a0main\u00a0reason\u00a0for\u00a0the\u00a0pond being non-functional for\u00a0several years is\u00a0the\u00a0total loss of\u00a0the\u00a0yield of\u00a0the\u00a0source of\u00a0water due to\u00a0the\u00a0progressive climate change and the\u00a0broken stream bed, through which the\u00a0remnants of\u00a0the\u00a0inflowing water seep into\u00a0the\u00a0ground (Fig. 10<\/span>). In\u00a0the\u00a0summer months, the\u00a0inflow of\u00a0water into\u00a0the\u00a0reservoir usually stops completely. That is\u00a0why Prague 4 Municipal Council is\u00a0working on\u00a0a\u00a0proposal to\u00a0collect rainwater from the\u00a0roofs of\u00a0the\u00a0Na Jezerce theatre buildings and to\u00a0supply the\u00a0lake (water reservoir) with water through an underground storage tank with an infiltration\u00a0gallery throughout the\u00a0year. It is\u00a0cheaper, and above all, more ecological than the\u00a0water supply from a\u00a0borehole or\u00a0the\u00a0theatre water supply line that was\u00a0considered in\u00a0the\u00a0original project design. The\u00a0total area of\u00a0the\u00a0theatre roofs is\u00a0sufficient enough in\u00a0terms of\u00a0rainwater runoff so that it\u00a0covers the\u00a0annual balance of\u00a0the\u00a0water reservoir; therefore, it should have a\u00a0year-round flow, which will have a\u00a0fundamental positive effect on\u00a0the\u00a0water quality in\u00a0the\u00a0reservoir. That is\u00a0why a\u00a0camera survey of\u00a0the\u00a0drainage and sewerage network around the\u00a0theatre took place last year, which will have to\u00a0be restored as\u00a0part of\u00a0the\u00a0project due to\u00a0its damage and clogging. At present, most of\u00a0the\u00a0rainwater from the\u00a0theatre roofs is\u00a0drained to\u00a0the\u00a0sewer without any further use.<\/span><\/p>\n

The\u00a0restoration\u00a0itself will consist of\u00a0restoration\u00a0of\u00a0the\u00a0lake basin\u00a0(the\u00a0bottom and walls of\u00a0the\u00a0reservoir) in\u00a0the\u00a0current or\u00a0only slightly modified layout and, above all, in\u00a0its deepening in\u00a0order to\u00a0improve water quality in\u00a0the\u00a0lake (currently, the\u00a0maximum depth would be only about 1 metre). The\u00a0banks will be restored, including the\u00a0possibility to\u00a0sit on\u00a0the\u00a0slopes, but overall the\u00a0location\u00a0should appear peaceful, not recreational. The\u00a0sound effect of\u00a0burbling water using a\u00a0system of\u00a0small artificial dams and the\u00a0construction\u00a0of\u00a0a\u00a0bridge over the\u00a0restored small watercourse above the\u00a0reservoir should also contribute to\u00a0this\u00a0sensation\u00a0(Fig. 11<\/span> and 12<\/span>). At the\u00a0same time, healthy mature and preserved trees in\u00a0the\u00a0vicinity should be preserved, and the\u00a0area should be sensitively complemented with other wetland and park vegetation\u00a0with appropriate furniture.<\/span><\/p>\n

At the\u00a0moment, the\u00a0city district has\u00a0requested a\u00a0water management assessment for\u00a0the\u00a0preparation\u00a0of\u00a0project documentation, which will be the\u00a0subject of\u00a0a\u00a0competition\u00a0in\u00a0the\u00a0spring of\u00a02023, and then a\u00a0joint zoning and construction\u00a0procedure will be initiated. The\u00a0Municipal Council of\u00a0Prague 4 subsequently assumes the\u00a0inclusion\u00a0of\u00a0the\u00a0investment in\u00a0the\u00a0action\u00a0plan for\u00a02024, so earthworks could start the\u00a0following year in\u00a0autumn. Comprehensive restoration\u00a0should lead to\u00a0the\u00a0restoration\u00a0of\u00a0the\u00a0former glory of\u00a0the\u00a0lake, which is\u00a0the\u00a0centre of\u00a0the\u00a0historical park and whose sensitive restoration\u00a0is\u00a0also an\u00a0absolute priority according to\u00a0the\u00a0opinion\u00a0of\u00a0the\u00a0citizens in\u00a0the\u00a0polls.<\/span><\/p>\n

\"\"<\/a><\/span>Fig. 9. Today\u2018s situation of the outlet of the groundwater drainage as an occasional inflow into the water reservoir (downstream view)<\/h6>\n
\"\"<\/a>Fig. 10. Dried and long-term defunct reservoir in\u00a0Jezerka Park<\/h6>\n
\"\"<\/a>Fig. 11 Visualization of the restoration of the inflow into the reservoir with a bridge and wetland vegetation\u00a0(view from the\u00a0same place as\u00a0in\u00a0Fig. 9<\/span>)<\/h6>\n
\"\"<\/a>Fig. 12 Visualization of the cascading concept of the inlet to the restored reservoir with the sound effect of falling water<\/h6>\n

This informative article has not been peer-reviewed.<\/p>\n","protected":false},"excerpt":{"rendered":"

Prague 4 district in\u00a0accordance with the\u00a0National Action Plan for\u00a0Adaptation to\u00a0Climate Change [1], Concept for\u00a0Protection\u00a0from the\u00a0Effects of\u00a0Drought of\u00a0the\u00a0Czech Republic [2], Strategy for\u00a0Adaptation\u00a0of\u00a0the\u00a0Capital City of\u00a0Prague to\u00a0Climate Change [3] and Methodology for\u00a0Rainwater Management in\u00a0the\u00a0City [4, 5], similarly to\u00a0other progressive-minded parts of\u00a0Prague, is\u00a0preparing investment actions to\u00a0support and strengthen green-blue infrastructure in\u00a0the\u00a0city. One of\u00a0the\u00a0most visible measures with truly demonstrable effects on\u00a0the\u00a0support of\u00a0biodiversity and water retention\u00a0in\u00a0the\u00a0landscape is\u00a0the\u00a0restoration\u00a0of\u00a0aquatic ecosystems. In\u00a0the\u00a0case of\u00a0the\u00a0capital city of\u00a0Prague and its most populous district of\u00a0Prague 4, these are mainly the\u00a0restoration\u00a0of\u00a0canalized (straightened or\u00a0piped) streams, or\u00a0desilting, strengthening or\u00a0comprehensive restoration\u00a0of\u00a0ponds and small water reservoirs in\u00a0a\u00a0highly urbanized landscape. A\u00a0specific area is\u00a0newly emerging bodies of\u00a0water in\u00a0places where water naturally tends to\u00a0be retained after longer periods of\u00a0rainfall and the\u00a0area thus cannot be used for\u00a0any other purpose, or\u00a0even in\u00a0places where there was\u00a0no body of\u00a0water before (although here in\u00a0the\u00a0narrower sense of\u00a0the\u00a0word it is\u00a0not restoration). For\u00a0such areas\u00a0created by\u00a0human intervention\u00a0in\u00a0order to\u00a0strengthen the\u00a0diversity of\u00a0aquatic and wetland vegetation, the\u00a0name artificial aquatic biotope has\u00a0been adopted. Let us have a\u00a0look at the\u00a0differences and specific pitfalls of\u00a0individual restoration\u00a0using three specific examples.<\/p>\n","protected":false},"author":8,"featured_media":18614,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[91,2,86],"tags":[2826,3124,3121,3125,3123,3122,3126],"coauthors":[30],"class_list":["post-21142","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-applied-ecology","category-from-the-world-of-water-management","category-hydraulics-hydrology-and-hydrogeology","tag-adaptation-measures","tag-artificial-aquatic-biotope","tag-biodiversity","tag-branik-biotope","tag-jezerka-park","tag-kunraticky-stream","tag-restoration-of-aquatic-ecosystems"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21142","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21142"}],"version-history":[{"count":7,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21142\/revisions"}],"predecessor-version":[{"id":32067,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21142\/revisions\/32067"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18614"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21142"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21142"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21142"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21142"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}