Member Statesare requested to carry out the first volcanic structures and it contains important groundwater bodies characterisation in accordance aquifers; with Artide 5 of the WFD in arder to identify water The alluvial secter, located in the centrai part of bodies at risk of failingto reach the WFD objectives. the river basin,near the main watercourses and in Water bodies at risk will be subject to a further; the intra-montane depressions,contains alluvial more detailed analysis. aquifers and marine and continental clastic deposits; This chapter describesgroundwater bodies in the Tevere river basin and examples offurther characterisation.

2.3. Initial characterisation

Hydrogeological structures and aquifers

The WFD provides indications on the analyses to carry out on groundwater; such as: location, perimeter; geological characteristics, pressures, and interdependence with surface aquatic and terrestrial ecosystems. First of all, the necessity of identifying a reference hydrogeological context emerged from the analyses carried out in the Tevere river basinoGeological and hydrostructural conditions influence aquifertypology and the interrelation between surface water and groundwater: Therefore, theTevere river basin..which is characterized by abundant groundwater resources, was schematically subdivided into four main sectors with different hydrostructural characteristics (Figure 17): The karstic sector, locatedin the easternpart of the river basin,is constitutedmainly by carbonate rocksand contains complex hydrostructures; The volcanic sector, locatedin the westernpart of the river basin,is composedof pery-thyrrenian Fig. 17 - MQin hydroge%gica/ sectorsin the Tevereriver basin The flysch sector, located in the upper part ofthe basin,is characterized by turbidites sequences consistingof marls, shales,clays and sandstoneswith evaporites.Only in the more permeable arenaceous sediments,water circulation sustainsan appreciable perennial base flow. During the initial characterisation,the aquifers contained in the flysch sector were neglected, becausethey are of local interest.

Karstic hydrostructures

Fifteen hydrostructures,main/y composed of carbonate rocks have been identified (Figure 18). These hydrostructures cover a surface area of about 7000 km2,ofwhich about 5220 km2fall within the Tevere river basin and contain the main groundwater resourcesthat feed most ofthe springsand ofthe Tevere river basin'sperennial hydrographic network. These groundwater resources are considered strategicfar their abundance (4 bi//ion m3/year)and their excellent quality. These"hydrostructures" are composed of rocks with sufficientlyhomogeneous characteristics, enclosed within generallywell-defined hydrau/icboundaries. The rocksthat form these hydrostructurestend to absorb, stare and dischargerainfall water into the surface throughthe springs.The hydrostructuresthat were dentified generallydo not contain only one significant iquifer;but rather overJappingaquifers that havenot let been identified and characterizedindividually: The minor hydrostructures (C2 - Monti di Gubbio; :3 - Monte Malbe and MonteTezio; C4 - Monte 5ubasio;C6 - Monte Cetona; C 10- ) :ig./8 - Kaf$tic hydrostructuresin the Tevereriver bas;n cover a surfacearea inferior to 60 km2and have a now of several hundreds of liters per secondoThe big hydrostructurallimits. mainly in meridian direction. hydrostructures (C I - north-eastern ; C5b - There are numerous perched and basai aquifers, that I/alnerina;C5a - ; C7 - Stifone - 5upply small and large springs, located in Montoro; C8 - Capore - north-eastern circumscribed areas (Iocalized springs) or distributed , C Il - Monti Lucretili and Monti Cornicolani; C 12 - along perennial watercourses (Iinear springs). southern Monti Sabiniand Monti Predestini) are There are o.ther two important karstic constituted mainly by carbonate successions(known hydrostructures (C9 - Monte Nuria - Monte ; as the Umbro-Marchigianaand Umbro- C 13 - north-western ) composed of successions)deposited in a pelagic domain and carbonate rocks of the typical -Abruzzo influenced by intense translational tectonics that succession, deposited in a carbonate shelf domain. produced folding structures with north-south These hydrostructures have more homogeneous vergenèe.Within these large hydrostructures, recent lithological characteristics compared to the Umbro- studies identified the existence of various Sabina succession and contai n extended basai overlapping aquifers and well-defined aquifersthat feed large localized and linear springs.

Arlicle 5 Reporl Average yearly effective infiltration rangesfrom about 500 mm far hydrostructures in transition areasto about 900 mm far hydrostuctures in a carbonate shelf complex. The baseflow of these hydrostructures in the Tevere river basin is superior to 100 m3/s. Table 5 shows the hydrostructures' values of the surfaceareaand of the mean and minimum dischargein the dry season.

AQuifers in the volcanic structures

The Mount Amiata, Mount , Mount Cimini, and Mount Sabatini volcanic structures are located on the right side ofthe Tevere valley.The Albano volcanic structure is located on the left side of the Tevere valley, downstream of the confluence with the River (Figure 19).The surface area covered by the volcanic structures accounts far 5,400 km2, of which 2,640 km2 fall within the Tevere river basino

Ali of these volcanic structures contain aquifersthat feed a vast network of mainly linear springs. The volcanic structures are composed of irregularly distributed pyroclastic rock and lavaflows. These rocks were formed on a clayey-sandysubstratum from the Plio-Pleistoceneepoch and, locally,on Fig./9 -Va/canic structures in the Tevererive, basin

:RE PllOT RIVERBASI alluvial depositsof the Paleotiber;that drainthe mouth of the Tevere river (M I). overlying pyroclasts. In total, nine main alluviafaquifers were identified, These aquifers composed of siliceous rocks are covering a total surfacearea of about 1260 km2, characterizedby very low salinity water: with an overall flow of about 9 m3/s. The mean effective infiltration ofthe MountVulsini, Cimini and Sabatinivolcanic structures is of about Groundwater abstraction 226 mm/year;with maximum values of about 280 mm/year and minimum values around 174 mm/year: Karstic sector The base flow measured in tl1e rl'veroed 15a6out 5.2 Groundwater resourcesstored in the karstic aquifers m3/s. are abundant and of excellent quality.Most ofthe The mean effective infiltration calculated in the Colli groundwater is abstracted far drinking water supply Albani volcanic structure is about 244 mm/year;with directly from the springsor from wells.The maximum values of 293 mm/year and minimum abstracted water is then distributed through a vast values of 206 mm/year: pipeline network. Water abstraction far drinking water supply is Significant aquifers in the fluvio-lacustrine estimated to about 25 m3/s,equal to about 790 alluvial and coastal deposits Mm3/y.

TheTevere river basin'sfluvio-lacustrine alluvial deposrts canbe divided into three largegroups according to their characteristicsand origin (Figure20). The first group comprisesthe fluvial alluvial deposits that border the Tevere river's course, from the sourceto the mouth (A I,A2 and A6), and analogousdeposits along the Pagliariver's course. The second group includesthe thick Pleistocene fluvio-lacustrinedeposits of the intermontane Gubbio valleys (A3), Valle Umbra (A4), Conca Temana(Al), Pianadi (A8) and Conca Reatina(A9), that were interested by important reclamationworks. The third group includes coastal aquifers near the

Fig. 20 - Main alluvial and coastal aquifers in the Tevere river basin

Article 5 Report The entire area falls within the river basinoThe Nera river flows through the Terni Valley from East to South-West. The area between the calcareous formations of the mountains and the alluvial deposits is represented by extended fluvial and lacustrine deposit outcrops, characterized by various granulometry. In the northem part an ampie strip of clastic deposits divides the Martani mountains that delimit the Valley in the north from the plain area. The main aquifer is located in the alluvial plain which extends far about 40 km2. It is composed of grave! and sand and it has a thickness of about 20-30 m.lt is located on fluvial and lacustrine deposits mostly made of conglomerates in the eastern part and of clayey deposits in the western partoThe covering is made of limestone-sandy terrain with a thickness of about IO meters in the eastern part and of a more reduced or null thickness in the centrai and westem parts of the valley.The aquifer is in hydraulic contact Fig. remi Valley with the Nera river that exerts its influence up to almost the margins of the deposits producing a Volcanic sector significant groundwater base flow and recharging the The estimated total withdrawals in the whole area of aquifer: the Vulsini,Cimini and Sabatinivolcanic structures, The clastic deposits of the area Iying at the base of comprising the areaswithin the Tevere river basin the Martani mountains are thicker than 50 m in the and the regional river basins,amounts to about 370 north and their thickness decreases towards south. Mm3/y.Totalwithdrawals in the Colli Albani volcanic They lie on conglomerate and travertine fluvial and structure amounts to about 180 Mm3/y. lacustrine deposits, where an aquifer of limited The following Tables 6 and 7 show the distribution of dimensions is situated. the abstracted water far different uses. In the area characterized by fluvial and lacustrine deposit outcrops, made up of sandy-conglomerate A/luvial sector or sandy-clayey sediments, there are small and not Alluvial aquifers are exploited far agricultural and very thick confined and unconfined aquifers. industriai use and to a lesserextent far drinking water supply. Quantitative status The regional monitoring network covers both the alluvial plain and the piedmont area of the Martani Mountains. 2.3.2 Examples of further The plain area is fed by the Nera river that manages characterisation to maintain the aquifer in equilibrium, despite the fact that the base flow is strongly modified by Alluvial aquifer (Terni Valley) withdrawals far hydropower use. The piezometric trends of some stations of 's The TerniValley has an extension of about 100 Hydrographic Services starting from the 50s' were squareJ<)lometers. It is formed by a centrai alluvial reconstructed on the basis of precedent studies. plain surrounded by a slightly steep belt that joins Fluctuations have always been limited and there have the plain area to the calcareous mountains that never been repercussions even consequently to the bound the valley (Figure 21). increased civil and industriai withdrawals, that amounted in certainperiods to over 1800l/s. Environmentalstatu~ Historical piezometric measurementsand Temi Valley'salluvial aquifer is characterized by a quantitative monitoring data carri ed out on a substantialhydrogeological equilibrium and the periodical basisconfirmed these indications. anthropogenic impact on the water resource quality The sector ofthe aquifer located in the centrai part is considerablymitigated by the Nera river's of the plain can be included in ClassA (in recharge.Thecentrai part ofthe aquifer;in direct accordance with the Italian nationallegislation). hydraulic contact with the river; shows good Regardingthe built-up area ofTerni, the quantitative ecological status.The more distant areasfrom the and chemical status cannot be defined at the river are characterized by sufficient environmental present moment because monitoring stations are status.Thesituation ofthe aquifer Iyingat the base of lacking and the hydrogeological situation is the Martani mountains is different. Its chemical and complex. quantitative status are compromised.therefore its The area at the feet ofthe Martani Mountains is environmental status is poor (Figure 22). subject to intense exploitation for drinking water On the basisof environmental status four supply.Withdrawals for drinking water supply groundwater bodies have been identified (Figure 23). accountfor more than 50%of mean annual recharge. Monitoring dat~ from 1998 to 2002 Volcanic aquifer (Colli Albani) shows an elevated variability in the water levels in The Colli Albani hydrogeological structure is located this sector ofthe aquifer;which is classifiedin Class in the lower part of the Tevere river basin, near the C. city of Rome (Figure 24). In the last 50 years this area has been subject to Chemica/ status growing pressures due to the expansion of urban TemiValley's alluvial aquifer beneflts from two settlements, industriai activity and agriculture (water- hydrogeological conditions that allow the aquifer to demanding crops).The waterdemand was mainly maintain the water's good qualitative condition: satisfied by groundwater abstraction from wells. recharge from the Nera river and elevated Consequently, in the last years, also due to a permeability. decrease of rainfall, the base flow in surface In the centrai area, at direct hydraulic contact with watercourses dropped by 50% (Figure 25). In the river; the water quality results good. Getting particular; the water level of Albano lake, which is in farther away from the river the aquifer direct contact with the aquifer; dropped of about 2 characteristics get worse due to an increase in the m (Figure 26). nitrates concentration, that however maintains Considering that surface base flow is fundamental in average values under the threshold of 50 mgil. sustaining aquatic ecosystems and that the flow of Bad water quality characteristics are evident in the water bodies receiving wastewater discharge detrital aquifer at the mar:gins of the Martani determines the quality status of water bodies, it is mountains. This aquifer is characterized by medium very important to maintain the base flow at a to low permeability and it does not benefit from the compatible level with the life of aquatic ecosystems karstic aquifer's recharge. The consequence is an and theachievement of good quality status. accumulation of poi Iutant input inthe aquifer: Hydrogeological balance calculations were carri ed The main problems are linked to the presence of out analyzing the spatial and temporal variabilityof pollutants from industriai activities. In particular; precipitations.and climatic conditions on a monthly monitoring of organic volatile halogen compounds basis, analyzing the effects of morphological, evidenced diffuse pollution from tetrach/oroethy/ene. lithological, pedological conditions, vegetation and This compound was identified in almost ali the land use on ruhoff and evapotranspiration with monitoring points of the network, although in elevated spatial detail, estimating the withdrawals. concentt:ations that were rarely superior to the This methodology allowed us to determine the ratio limits imposed by law.Among these compounds rare betwe~n withdrawals and effective infiltration. positive cases of trich/oroethy/ene and trich/oroethano On the basis ofthese calculations four balance units were identified. have been identified. The balance units have different

Article 5 Report withdrawal/recharge ratios and can be considered as Mount Cuccois situatedin the westernmargin of four water bodies (Figure 27). the Umbria-Marche Apennines and it is constituted by calcareoussequences that go from the Jurassicto Karstic aquifers (Mount Cucco) the Cretaceous epoch and by arenaceousf1ysch Different aquiferswere identified in the C I structure. from the Miocene epoch. Detailed studiesallowed far the identificationand The structure of Mount Cucco is an asymmetrical characterisationofthe aquifers'hydro-structurallimits, anticline overtumed towards east on the most rechargeareas, springs, and piezometric fields. external anticlinal folds;the eastern and westem Figure28 shows an example of more detailed slopes and the inner part of the structure are studies carried out in the area of Mount Cucco, in characterized by evident tectonic features (faults).ln the Umbria-Marcheregion. particular;two important faults delimit the centrai

~ -- \:i -

1== -- ~ 1J --

Fig. 22 - Environmental status ofthe Temi Valley's al/uvial aquifer

Fig. 24 - The Colli A/ban; hydrogeologica/ structure

Fig. 23 - Groundwater bodies in d1e Temi Va/ley's a/luvial aquifer Fig. 25 -Flow measurements in a river of the volcanic sector

rEVEREPllOT RIVERBASIN E " E E --- ~ E ! CI c .~ 'm .c ... >. 'ai "t: f (O al >.

Ag. 26 - The red line shows the hydrometric measurements in theAlbano lake between 1995-/999,compared to mean annual predpitotions measured in the pluviometric stotions O( Froscati in the some period

Calcareous massifnucleus, that culminates in cavities,for 30 km and a maximum depth of922 m. correspondence with Mount Cucco, uplifting it in A vast recharge area was identified in the nucleus of respect to the south-eastern and north-eastem the hydrogeological structure. The recharge area is sectors. Furthermore, the nucleus is characterised by hydraulically delimited by overthrust folds towards a vast network of fractures and by highly developed NE and bythe fucoid Mari complex.The calcareous hypogeous karst phenomena,with more than 50 Scaglia belt, externally delimited by prevalently mari complexes, was identified in the north-westem, western, and south-western slopes. It is possible to identify two distinct aquifers: a basai aquifer in the calcareous massif ofthe structure and a peripheral aquifer in the Scaglia.The aquifers' perennial springs are located alongthe impermeable boundaries and are represented by linear springs distributed along watercourse~ and to a lesser extent by localized springs. The Scirca spring, the largest localized spring, with a tlow of 230 l/s, is exploited far drinking water supply. Prov-isional,establishment of objectives

The characterisationactivity led to the conclusion that it is necessaryto carry out a typology analysis also on gròundwater resources. In theTevere river basin we identified two main typologiesfor which different objectives must be set: . Aquifers that represent strategic water resources, Fig.27 - ColliA/bani hydrogeo/ogica/balance unir that mustbe safeguardedand for whichno

Article 5 Report chemico-physicalalterations are allowed(this aspect is hardly dealt with in the WFD and it is completely missingin the Daughter Directive on groundwater); Aquifers at risk. impacted by signiticantpressures, far which the objective is recovery of chemico- physicalstatus and quantitative status,in accordancewith the indications contained in the Daughter Directive, although the Daughter- Directive is lackingin regard to quantitative aspects and to the combined effect of quantitative and qualitative aspects.

[;:J

. :.., , Il. ==:""--' .=.:..~~- . =::--' .:'-:"==-- =:;;,-'-' ~:.'" ., Authors . ~~-- =:-.::;'" ~'S=.. Manuela Ruisi ~~~,- """--- Contributions Carlo Boni;Giuseppe Capelli.Angiolo Martinelli. Fig. 28 - Hydrogeologica/ map or Mount Cucco Roberto Mazza.Alessandra Santucci