PROLINE-CE WORKPACKAGE T2, ACTIVITY T2.1 SET UP OF PILOT SPECIFIC MANAGEMENT PRACTICES D.T2.1.4 DESCRIPTIVE DOCUMENTATION OF PILOT ACTIONS AND RELATED ISSUES PILOT ACTION PAC2.1: WELL FIELD DRAVLJE VALLEY IN LJUBLJANA September, 2017 Lead Institution University of Ljubljana Contributor/s “PP4, PP5” Lead Author/s Barbara Čenčur Curk, Jerca Praprotnik Kastelic, Ajda Cilenšek Date last release Sep 2017 Contributors, name and surname Institution Barbara Čenčur Curk University of Ljubljana, NTF Jerca Praprotnik Kastelic University of Ljubljana, NTF Primož Banovec University of Ljubljana, FGG Ajda Cilenšek University of Ljubljana, FGG Matej Cerk University of Ljubljana, FGG Branka Bračič Železnik Public Water Utility JP VO-KA 1 TABLE OF CONTENTS 1. Introduction ............................................................................................................................................................ 3 2. Basic data about pilot action .................................................................................................................................. 3 2.1. Geographical description ......................................................................................................................................... 3 2.2. Geological description ............................................................................................................................................. 5 2.3. Pedology .................................................................................................................................................................. 6 2.4. Climate characteristics ............................................................................................................................................ 8 2.5. Hydrology ................................................................................................................................................................ 9 2.5.1. Surface waters ................................................................................................................................................. 9 2.5.2. Flood issues .................................................................................................................................................... 11 2.6. Hydrogeology ........................................................................................................................................................ 13 2.7. Land use ................................................................................................................................................................. 15 3. Water supply in the pilot action .............................................................................................................................17 3.1. Drinking water sources .......................................................................................................................................... 17 3.2. Drinking water protection ..................................................................................................................................... 18 4. Protected areas .....................................................................................................................................................20 5. Main identified problems / conflicts ......................................................................................................................21 6. References .............................................................................................................................................................23 2 1. Introduction Land use and climate change have significant impacts on water resources in general and drinking water resources in particular. Drinking water protection is already an integrated part of some land-use management practises, but lagging behind with implementation and realisation. The main objective of PROLINE-CE project is improved protection of drinking water resources as well as protection against floods/droughts in an integrated land use management approach. PROLINE- CE will encompass efficient implementation of innovative best practices of land use and water protection in pilot actions, aiming at transnational levelling of fundamental visions, elaboration of policy support and implementation support at operational level. The public company JP VODOVOD-KANALIZACIJA d.o.o. is the largest water supply company in Slovenia. In accordance with legislation, the public water supply service has to have the reserve drinking water source to increase reliability and safety of public water supply. On the basis of previous geological and hydrogeological research Dravje valley was selected for reserve water well field. Dravlje valley is a settled area, crossing by highway and with large open spaces adjacent to a Natural Park of hilly area. Because of its location in the suburbs of Ljubljana, there is also a high pressure on land use. Dravlje valley is also a flood area with not properly regulated surface waters coming from hinterland. Most of these waters are lead to the urban sewage system, which in high waters cannot receive so much water; on the other hand leading of surface waters to sewers is an adequate solution form the environmental point of view. In the future more frequent high waters because of climate change are foreseen; therefore solutions and measures for tackling this problem should be developed. For this harmonized land use and water resources management is a prerequisite for quality of life and drinking water in this area, therefore for Slovenian Pilot Action Dravlje valley in Municipality of Ljubljana was selected. 2. Basic data about pilot action 2.1. Geographical description Selected pilot action area (PAA) represents Glinščica river basin. In the north side extents to the forest area of Toško Čelo and Mirni vrh. The east watershed goes from the urban area Dravlje and Šiška over the Šišenski hill and Rožnik to the watercourse Gradaščica, which represents the southernmost point of the basin. In the western direction the watershed goes through urban area from Brdo to Tičnica, and then towards the north via the Stražni vrh, Preval to Toško Čelo. 3 Toško Čelo Dravlje Podutik Koseze Glinščica Pržanec Rožnik Rožna Dolina Figure 1: LIDAR (surface) data of the PAA (ARSOa, 2017) River Glinščica spring is under a hill Toško Čelo, in Podutik enters the flatland of Ljubljana plain. Then it runs thorugh the edge of Ljubljansko barje along hill Rožnik. In the urban area Vič Glinščica flows into Gradaščica (which then flows into the Ljubljanica). Relief of the Glinščica basin is quite diverse from hilly part in the east to the plain area in the southern part (Figure 1). 4 2.2. Geological description The Ljubljana Field and Ljubljana Moor are depressions, created during Plio-Quaternary multiphase tectonic submersion. The Ljubljana Field depression cut from the faults was filled with river sediments during Plistocene and Holocene eras. In the same periode the Ljubljana Moor depression and Dravlje valley were filled with river and moor sediments (Petauer, 2003). The oldest rocks in the Pilot action Area (PAA) belong to the Carboniferous-Permian black clayish shales and Val Gardena clastic sedimentary rocks, separated by erosional disconformity. They are located on the slopes of Rožnik hill and Toško Čelo (Figure 1), which represent hinterland of river Glinščica. Triassic beds are found with great lithologic diversity, which is characterized by lower Triassic beds rhythmically changing from sandy clay beds to Limestone and Dolomite. In the upper part dolomite (Main Dolomite) and limestone beds (Dachstein limestone with Megalodon shells) dominate, overlain by dolomite beds which continue to middle and upper Triassic. In lower Jurassic thick bedded Liassic limestone occurs (Grad & Ferjančič, 1976; Novak, 2000). From the hills and slopes, river Glinščica and smaller streams transport sediments to the lower parts and flatland. The Piezometer OP-12/03 shows more than 80 meters of clay and gravel sediments transported and deposited in Koseze area. Clay prevails in the upper 15 m, from this depth downwards sandy gravels and conglomerate are deposited (Petauer, 2003). 5 Figure 2: Geological map (GeoZS, 2017) 2.3. Pedology The pedology in Pilot Area is very diverse. The area is covered by seven different types of soil (Figure 3). There are also urban areas and one Quarry. On the slopes of Toško Čelo and Šišenski hill, soil type Cambisol prevails. Cambisol is a young soil at depth 25 - 50 cm, with purely developed horizons or containing homogenous sand. Minor differences between soil subtypes are in colour: Chromic Cambisol is reddish coloured and in base saturation, whereas brownish Dystirc Cambisol contains less than 50% base saturation. On some smaller parts of slopes, Rendzinic Leptosol type of soil is present. Leptosols are soils with a very shallow 6 profile depth, containing large amounts of gravel and they often cover mountain slopes on Limestone or Dolomite beds. Figure 3: Pedological map (GURS, 2017) In the Flatland where river Glinščica deposits river sediments, Gleyosol and Planosol are located. Both are Eutric subtype of soil and have 75 percent or more base saturation. Gleysols and Planosols are characterized by a subsurface layer of clay accumulation and are poor in plant nutrients (FAO, 2017). An urban area contains small amount of soil, mainly high population density and infrastructure. 7 2.4. Climate characteristics