Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

Home , Azat (river), Little Ararat, Masis (village), Vedi, Yeghegnavan

Scientific Investigations Report 2017–5163

U.S. Department of the Interior U.S. Geological Survey Cover. This astronaut photograph, taken from the International Space Station, highlights a segment of the international border between Armenia and Turkey. The Aras River separates the two countries, with Armenia to the north-northeast and Turkey to the south-southwest. Extensive green agricultural fields are common on both sides of the river (upper part of image), as well as a number of gray-to- tan urban areas including Yerevan (image top, slightly left of center) and Artashat and Armavir in Armenia, and Iğdır in Turkey. While there have been efforts to normalize diplomatic relations between the two countries in recent years, the Armenia-Turkey border remains officially closed. The dominant geographic feature in the region is Mt. Ararat, also known as Agri Dagi. The peak of Ararat, a large stratovolcano that last erupted in 1840 according to historical records, is located approximately 40 kilometers to the south of the Armenia-Turkey border. A lower peak to the east, known as Lesser or Little Ararat or Lil Sis, is also volcanic in origin. Dark gray lava flows to the south of Mt. Ararat are located near the Turkish border with Iran. While this border is also closed along much of its length, official crossing points allow relatively easy travel between the two countries. The white, glacier-clad peak of Mt. Ararat is evident at image center; dark green areas on the lower slopes indicate where vegetation cover is abundant. A large lake, Balik Golu or Fish Lake, is visible to the west (image lower left). Source of photograph and description: National Aeronautics and Space Administration Earth Observatory, ISS Expedition 28 crew, July 8, 2011.

Back cover. Photographs of the study area showing Mt. Ararat in the background. Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

By Joshua F. Valder, Janet M. Carter, Colton J. Medler, Ryan F. Thompson, and Mark T. Anderson

Scientific Investigations Report 2017–5163

U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior RYAN K. ZINKE, Secretary U.S. Geological Survey William H. Werkheiser, Deputy Director exercising the authority of the Director

U.S. Geological Survey, Reston, Virginia: 2018

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Suggested citation: Valder, J.F., Carter, J.M., Medler, C.J., Thompson, R.F., and Anderson, M.T., 2018, Hydrogeologic framework and groundwater conditions of the Ararat Basin in Armenia: U.S. Geological Survey Scientific Investigations Report 2017–5163, 40 p., https://doi.org/10.3133/sir20175163.

ISSN 2328-0328 (online) iii

Acknowledgments

The authors thank Magda Avetisyna, Aram Gevorgyan, Lilith Harutyunyan, and Benyamin Zakaryan, U.S. Agency for International Development (USAID) contractors with the Advanced Science and Partnership for Integrated Resource Development (ASPIRED) program, for their help obtaining Armenian hydrologic and geologic data, translation, hospitality, and collaboration for this study. Staff of the Hydrogeological Monitoring Center in Yerevan, Armenia, collected data on the status of wells, water levels, and basic field water-quality constituents in the Ararat Basin during the summer of 2016.The authors also thank Naram Chanmugam, Patrick Meyer, and Marina Vardanyan, USAID, for providing funding and guidance for this study and for their hospitality in Armenia.

Contents

Acknowledgments...... iii Abstract...... 1 Introduction...... 2 Purpose and Scope...... 2 Description of Study Area...... 2 Hydrogeologic Setting...... 5 Data and Methods...... 5 Lithologic Data...... 5 Hydrologic Data...... 8 Groundwater Data...... 8 Water-Quality Data...... 10 Hydrogeologic Framework...... 10 Areal Extent...... 11 Hydrogeologic Units...... 12 Hydrogeologic Unit 1...... 12 Hydrogeologic Unit 2...... 12 Hydrogeologic Unit 3...... 12 Hydrogeologic Unit 4...... 17 Hydrogeologic Unit 5...... 17 Hydrogeologic Unit 6...... 18 Hydrogeologic Unit 7...... 18 Hydrogeologic Unit 8...... 18 Hydrogeologic Unit 9...... 18 Groundwater Conditions...... 19 Flowing and Nonflowing Aquifer Conditions...... 19 Potentiometric Surface...... 19 Water Use...... 26 Changes in Groundwater Levels and Well Discharge...... 26 Water Quality...... 28 Summary...... 38 References Cited...... 40

Figures

1. Map showing location of the Ararat Basin (study area) in Armenia and Turkey...... 3 2. Map showing digital elevation model of Ararat Basin...... 4 3. Chart showing hydrogeologic units of the study area interpreted from lithologic logs as described in table 1...... 7 4. Photographs showing collection of hydrologic data on March 2, 2016, as part of field training in Armenia...... 9 5. Photograph showing collection of stable-isotope sample from a flowing well (U.S. Geological Survey site 400250044235601) in the Ararat Basin, Armenia...... 11 vi

6. Three-dimensional special interpretation of the Ararat Basin, Armenia, derived from lithologic logs provided by the Advanced Science and Partnerships for Integrated Resource Development group...... 13 7. Map of three subbasin areas and three cross sections of the Ararat Basin, Armenia, used to define the nine hydrogeologic units...... 14 8. Graphs showing number and distribution of wells used to generate thicknesses for each of the nine hydrogeologic units in the Ararat Basin, Armenia...... 15 9. Maps showing thickness of all nine hydrogeologic units in the Ararat Basin, Armenia...... 16 10. Map showing location of flowing and nonflowing wells in 2016 and locations of the 1984, 2007, and 2016 pressure boundaries between flowing and non-flowing wells in the study area of the Ararat Basin in Armenia...... 20 11. Map showing location of wells included in the 2016 well inventory by hydrogeologic unit in the study area of the Ararat Basin in Armenia...... 21 12. Map showing potentiometric surface of hydrogeologic unit 2 in the study area of the Ararat Basin in Armenia...... 22 13. Map showing potentiometric surface of hydrogeologic unit 4 in the study area in the Ararat Basin in Armenia...... 23 14. Map showing potentiometric surface of hydrogeologic unit 6 in the study area of the Ararat Basin in Armenia...... 24 15. Map showing potentiometric surface of hydrogeologic unit 8 in the study area of the Ararat Basin in Armenia...... 25 16. Maps showing spatial distribution of wells with various water uses in 2016 in the study area of the Ararat Basin in Armenia...... 27 17. Photograph showing an abandoned well flowing water to the land surface in November 2015 in the Ararat Basin in Armenia...... 28 18. Map showing location of and well discharge from nonoperational, abandoned flowing wells with discharge to waste in 2016 in the study area of the Ararat Basin in Armenia...... 29 19. Pie diagram showing percentage of wells by use of water based on wells inventoried in 2016 in the study area of the Ararat Basin in Armenia...... 30 20. Map showing well discharge rates for flowing wells used for irrigation in the study area of the Ararat Basin in Armenian in 2016...... 31 21. Map showing well discharge rates for flowing wells used for fish farming in the study area of the Ararat Basin in Armenia in 2016...... 32 22. Map showing locations of current (2016) and previous wells used for drinking water in the study area of the Ararat Basin in Armenia...... 33 23. Map showing difference in hydraulic heads between 2007 and 2016 in the study area of the Ararat Basin in Armenia...... 34 24. Map showing spatial distribution of specific conductance in water from wells in the study area of the Ararat Basin in Armenia in 2016...... 35 25. Bar chart showing distribution of ranges of specific conductance values in the study area of the Ararat Basin in Armenia in 2016...... 36 26. Map showing spatial distribution of water temperature in wells in the study area of the Ararat Basin, Armenia, in 2016...... 37 27. Graph showing isotopic composition of water samples from wells and Hrazdan River in the study area of the Ararat Basin compared to Global Meteoric Water Line (Craig, 1961)...... 38 vii

Tables

1. Lithologic descriptions, land-surface elevations, geologic layer thicknesses, and hydrogeologic units of the Ararat Basin, Armenia...... 2 2. Lithologic descriptions, thickness, and water-bearing potential for 24 unique lithological materials based on lithologic logs for wells drilled in the Ararat Basin, Armenia...... 6 3. Water-level and well discharge data collected in the Ararat Basin by U.S. Geological Survey in March 2016...... 9 4. Hydrologic data provided to the U.S. Geological Survey from the 2016 well inventory conducted in the Ararat Basin, Armenia, by Armenian partners...... 10 5. Historical water-level data from 2007 in the Ararat Basin, Armenia, provided to the U.S. Geological Survey by Armenian partners...... 10 6. Historical water-level and well yield data from various dates ranging from 1981 to 2013 in the Ararat Basin, Armenia...... 10 7. Water-quality data collected or analyzed by U.S. Geological Survey in March 2016 in the Ararat Basin, Armenia...... 11 8. Summary of each unit detailing the number of wells used in defining the geologic material, the average unit thickness across the Ararat Basin, and the maximum measured and interpolated thicknesses within each of the hydrogeologic units...... 17

Conversion Factors

International System of Units to U.S. customary units

Multiply By To obtain Length millimeter (mm) 0.03937 inch (in.) meter (m) 3.281 foot (ft) kilometer (km) 0.6214 mile (mi) Area hectare (ha) 2.471 acre square kilometer (km2) 247.1 acre hectare (ha) 0.003861 square mile (mi2) square kilometer (km2) 0.3861 square mile (mi2) Volume milliliter (mL) 0.03381 ounce, fluid (fl. oz) liter (L) 0.2642 gallon (gal) cubic meter (m3) 264.2 gallon (gal) cubic kilometer (km3) 0.2399 cubic mile (mi3) Flow rate liter per second (L/s) 15.85 gallon per minute (gal/min) Mass kilogram (kg) 2.205 pound avoirdupois (lb) metric ton (t) 2204.62 pound avoirdupois (lb) viii

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows: °F = (1.8 × °C) + 32. Temperature in degrees Fahrenheit (°F) may be converted to degrees Celsius (°C) as follows: °C = (°F – 32) / 1.8.

Datum

Horizontal coordinate information is referenced to the World Geodetic System of 1984 (WGS 84). Vertical coordinate information is referenced to the World Geodetic System of 1984 (WGS 84). Elevation, as used in this report, refers to distance above the vertical datum.

Supplemental Information

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (µS/cm at 25 °C). Results for measurements of stable isotopes of an element (with symbol E) in water, solids, and dissolved constituents commonly are expressed as the relative difference in the ratio of the number of the less abundant isotope (iE) to the number of the more abundant isotope of a sample with respect to a measurement standard.

Abbreviations

δ delta ASPIRED Advanced Science and Partnerships for Integrated Resource Development DEM digital elevation model GIS geographic information system 1H protium 2H deuterium 16O oxygen-16 18O oxygen-18 USAID U.S. Agency for International Development USGS U.S. Geological Survey Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

By Joshua F. Valder, Janet M. Carter, Colton J. Medler, Ryan F. Thompson, and Mark T. Anderson

Abstract interbedded dense clays, gravels, sands, volcanic basalts, and andesite deposits. Previously published cross sections and well Armenia is a landlocked country located in the moun- lithologic logs were used to map nine general hydrogeologic tainous Caucasus region between Asia and Europe. It shares units. Hydrogeologic units were mapped based on lithology borders with the countries of Georgia on the north, Azerbai- and water-bearing potential. Water-level data measured in the jan on the east, Iran on the south, and Turkey and Azerbaijan water-bearing hydrogeologic units 2, 4, 6, and 8 in 2016 were on the west. The Ararat Basin is a transboundary basin in used to create potentiometric surface maps. In hydrogeologic Armenia and Turkey. The Ararat Basin (or Ararat Valley) is unit 2, the estimated direction of groundwater flow is from an intermountain depression that contains the Aras River and the west to north in the western part of the basin (away from its tributaries, which also form the border between Armenia the Aras River) and from north to south (toward the Aras and Turkey and divide the basin into northern and southern River) in the eastern part of the basin. In hydrogeologic unit regions. The Ararat Basin also contains Armenia’s largest agri- 4, the direction of groundwater flow is generally from west to cultural and fish farming zone that is supplied by high-quality east and north to south (toward the Aras River) except in the water from wells completed in the artesian aquifers that under- western part of the basin where groundwater flow is toward lie the basin. Groundwater constitutes about 40 percent of all the north or northwest. Hydrogeologic unit 6 has the same water use, and groundwater provides 96 percent of the water general pattern of groundwater flow as unit 4. Hydrogeologic used for drinking purposes in Armenia. Since 2000, ground- unit 8 is the deepest of the water-bearing units and is confined water withdrawals and consumption in the Ararat Basin of in the basin. Groundwater flow generally is from the south to Armenia have increased because of the growth of aquaculture north (away from the Aras River) in the western part of the and other uses. Increased groundwater withdrawals caused basin and from west to east and north to south (toward the decreased springflow, reduced well discharges, falling water Aras River) elsewhere in the basin. levels, and a reduction of the number of flowing artesian wells In addition to water levels, personnel from Armenia’s in the southern part of Ararat Basin in Armenia. Hydrogeological Monitoring Center also measured specific In 2016, the U.S. Geological Survey and the U.S. Agency conductance at 540 wells and temperature at 2,470 wells in the for International Development (USAID) began a coopera- Ararat Basin using U.S. Geological Survey protocols in 2016. tive study in Armenia to share science and field techniques The minimum specific conductance was 377 microsiemens per to increase the country’s capabilities for groundwater study centimeter (µS/cm), the maximum value was 4,000 µS/cm, and modeling. The purpose of this report is to describe the and the mean was 998 µS/cm. The maximum water tempera- hydrogeologic framework and groundwater conditions of the ture was 24.2 degrees Celsius. An analysis between water Ararat Basin in Armenia based on data collected in 2016 and temperature and well depth indicated no relation; however, previous hydrogeologic studies. The study area includes the spatially, most wells with cooler water temperatures were Ararat Basin in Armenia. This report was completed through within the 2016 pressure boundary or in the western part of the a partnership with USAID/Armenia in the implementation of basin. Wells with generally warmer water temperatures were its Science, Technology, Innovation, and Partnerships effort in the eastern part of the basin. through the Advanced Science and Partnerships for Integrated Samples were collected from four groundwater sites Resource Development program and associated partners, and one surface-water site by the U.S. Geological Survey in including the Government of Armenia, Armenia’s Hydrogeo- 2016. The stable-isotope values were similar for all five sites, logical Monitoring Center, and the USAID Global Develop- indicating similar recharge sources for the sampled wells. ment Lab and its GeoCenter. The Hrazdan River sample was consistent with the ground- The hydrogeologic framework of the Ararat Basin water samples, indicating the river could serve as a source of includes several basin-fill stratigraphic units consisting of recharge to the Ararat artesian aquifer. 2 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

Introduction artesian aquifers in the basin (Nalbandyan, 2012; Carter and others, 2016). Armenia is a landlocked country located in the moun- In 2016, the U.S. Geological Survey (USGS) and the tainous Caucasus region between Asia and Europe. It shares U.S. Agency for International Development (USAID) began borders with the countries of Georgia on the north, Azerbaijan a cooperative study with Armenia to share science and field on the east, Iran on the south, and Turkey and Azerbaijan on techniques to increase the country’s capabilities for groundwa- the west (fig. 1). Armenia has an area of about 29,700 square ter study and modeling (Carter and others, 2016). This study kilometers (km2). Its population in 2015 was approximately is in partnership with USAID/Armenia in the implementation 3 million (U.S. Census Bureau, 2016). Approximately one- of its Science, Technology, Innovation, and Partnerships effort third of the population lives in the capital city of Yerevan through the Advanced Science and Partnerships for Integrated (World Population Review, 2016). Groundwater supplies Resource Development (ASPIRED) program and associated 96 percent of the water used for drinking water purposes, partners, including the Government of Armenia, Armenia’s and about 40 percent of all water withdrawn in the country is Hydrogeological Monitoring Center, and the USAID Global from groundwater (Yu and others, 2014). Agriculture depends Development Lab and its GeoCenter. These techniques can heavily on groundwater irrigation and more than 80 percent be used by groundwater-resource managers, such as those in of the gross crop production is from irrigated lands (Yu and Armenia’s Ministry of Nature Protection, to understand and others, 2014). predict the consequences of their resource management deci- The Ararat Basin lies between the Caucasus Mountains sions. One of the objectives for this study was to characterize to the north and the Armenian Plateau to the south. The Aras the hydrogeologic framework and groundwater conditions in River divides the basin into northern and southern regions and the Ararat Basin. also forms Armenia’s border with Turkey (fig. 1). Elevations within the Ararat Basin range from 800 to 1,000 meters (m) Purpose and Scope (fig. 2, table 1). The Ararat Basin occupies an area of about 2 1,300 km (Armenian Branch of Mendez England and Associ- The purpose of this report is to describe the hydrogeo- ates, 2014). About 8 percent of the population of Armenia logic framework and groundwater conditions of the Ararat lives in the Ararat Basin (U.S. Agency for International Devel- Basin study area in Armenia. Specifically, the report describes opment, 2008). The Ararat Basin supports the largest agricul- the lithology and hydrogeologic units in the study area. The ture and fish farming zones in Armenia (Yu and others, 2014). hydrogeologic framework and groundwater conditions are characterized through existing geologic maps, lithologic data Table 1. Lithologic descriptions, land-surface elevations, from drilled wells, remote sensing imagery, well records and geologic layer thicknesses, and hydrogeologic units of the logs, and groundwater-level measurements and other field Ararat Basin, Armenia (available online at https://doi.org/10.3133/ data collected across the basin. For the artesian units that sir20175163). underlie the Ararat Basin study area, the hydraulic properties, discharge, and changes in hydraulic head and storage through Since 2000, aquaculture demands and other uses have 2016 are described. increased groundwater withdrawals in the Ararat Basin. Increased groundwater withdrawals resulted in decreased springflows, reduced well discharges, lower well water levels, Description of Study Area and a reduction of the number of flowing artesian wells in the southern part of Ararat Basin (Armenia Branch of Mendez The Ararat Basin (also known as the Ararat Valley) is England and Associates, 2014; Yu and others, 2014). In 2013, an intermountain depression that contains the Aras River and groundwater use by aquaculture alone exceeded the sustain- its tributaries (Armenian Branch of Mendez England and able level of groundwater resources, and the total groundwater Associates, 2014). The Aras River has a drainage area of use for all purposes in the Ararat Basin was 1.6 times the approximately 31,500 km2, of which 14,900 km2 is in Armenia sustainable level (Yu and others, 2014). Increased groundwater and 16,600 km2 is in Turkey (Armenian Branch of Mendez withdrawals have also affected other water uses. Flowing England and Associates, 2014). The study area includes the artesian wells supplying drinking and irrigation water to Ararat Basin in Armenia (fig. 2) and is slightly larger than 31 communities have ceased flowing. The Armenian Nuclear the “Ararat artesian basin” defined by Armenian Branch of Power Plant at Metsamor (fig. 1) cannot meet water require- Mendez England and Associates (2014) because the study ments (Yu and others, 2014). Streamflows and lake levels have area boundary was expanded to include locations of all wells diminished as a result of aquifer depletion (Armenia Branch inventoried in 2016. of Mendez England and Associates, 2014). Additionally, there The Ararat Basin is the most arid region of Armenia are numerous abandoned flowing wells in the Ararat Basin with annual precipitation of about 200–250 millimeters (mm) and some continue to discharge water to the land’s surface, (Nalbandyan, 2012). Despite the arid climate, this region creating environmental hazards and continued depletion of the contains the country’s largest agricultural and fish farming Introduction 3 4445E

AAA AAA Vedi River Vedi 394953044375601 AASA AASA 395751044322601 395751044322601 Aras River

A A

401110044295401 401110044295401 Arat River Arat is U.S. Geological Survey site identification number (table 7) 4430E Study area Ararat Basin Site visited in March 2016 —Number City EPLANATION

MASIS MASIS Hrazdan River Hrazdan 394953044375601 394953044375601 CMIADI CMIADI 400250044235601 400250044235601 400347044223901 400347044223901

IODO IODO

i 15 MILES

k a s a 4415E K MSAMO 10

Metsamor River 15 KILMETERS 10 5 Aras River 5 AMAI AMAI 0 0 Base from U.S. Geological Survey Shuttle Mission Radar Topography Geodetic System of 184 proection, orld Mercator Auxiliary Sphere eb 4400E

S AZERBAIJANIN A T N U

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TURKEY A 4345E Figure 1. 4015N 4000N 345N 4 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia 4445E

AAA AAA Vedi River Vedi AASA AASA Aras River

A A Azat River Azat 4430E

MASIS MASIS Hrazdan River Hrazdan 15 MILES CMIADI CMIADI 10

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Metsamor River 0 0 Base from U.S. Geological Survey Shuttle Mission Radar Topography Geodetic System of 184 proection, orld Mercator Auxiliary Sphere eb

AMAI AMAI Aras River Aras High: 5,101 Low: 730 Meters 4400E (30-meter resolution) Digital elevation model EPLANATION igital elevation model of Ararat Basin. Study area Ararat Basin City D

Figure 2. 4015N 4000N 345N Data and Methods 5 zone supported by generally high-quality water from wells For this study, lithostratigraphic units were grouped completed in the artesian aquifer (Yu and others, 2014). into nine hydrogeologic units. The units were determined The water also is suitable for human consumption using published cross sections and well lithologic logs from without additional treatment (Yu and others, 2014). The annexes 2 and 3 of a study by the Armenian Branch of Mendez artesian aquifer is contained in Quaternary deposits of lava, England and Associates (2014). The study described three primarily porous and fractured basalts. Approximately water-bearing groundwater units, including one unconfined 80 percent of springs in the Ararat Basin originate from these unit and two confined units. The confined units were under lava deposits (Nalbandyan, 2012). Recharge to the artesian artesian conditions in some areas of the basin (Armenian aquifer is through direct infiltration of precipitation and loss of Branch of Mendez England and Associates, 2014). For the flow in surface streams, especially in upland areas. nine units mapped in this report, four were identified as having The mean annual water withdrawal from surface-water a high water-bearing potential. These four units consisted of and groundwater sources in Armenia is about 8,000 cubic interbedded sands and gravels and fractured basalts (fig. 3). meters per hectare, with groundwater irrigation consuming about 70 percent of that withdrawal (Nalbandyan, 2012). Groundwater withdrawn from the basin’s artesian aquifer is used for municipal, irrigation, energy, industrial, and aqua- Data and Methods culture. In July 2008, the 477 water withdrawal points in the basin were used for the following purposes: 63 percent for This section describes the data acquisition and analysis irrigation, 12 percent for energy, 11 percent for industrial, methods used to develop the hydrogeologic framework and to 9 percent for drinking, and 6 percent for aquaculture (sums to describe the groundwater conditions in the Ararat Basin. Data 101 percent due to rounding; U.S. Agency for International were available only for the northern region of the Ararat Basin Development, 2008). in Armenia, which is hereafter referred to as the study area. Within the Ararat Basin, about 267 fish farms were developed to raise trout, sturgeon, and other cold-water Lithologic Data fish, with about 190 fish farms in operation in 2015 (Meyer, 2015). For fishery purposes, the Ministry of Nature Protec- Lithologic data for the hydrogeologic framework were tion issued permits for 576 wells with a total discharge rate of obtained from researchers from the ASPIRED program. approximately 43,200 liters per second (L/s) (Meyer, 2015). ASPIRED researchers translated paper lithologic logs Armenia produces about 11,500 metric tons of fish annually recorded in Russian language to Armenian and English for (Meyer, 2015). more than 2,500 wells completed in the study area. ASPIRED researchers provided the USGS with English descriptions of 24 unique lithologic layers (table 2). The water-bearing poten- Hydrogeologic Setting tial of each of the 24 unique lithologic layers (table 2) was The Ararat Basin is a transboundary basin located in determined based on interpretations of the English lithologic Armenia and Turkey. The Ararat Basin is an asymmetrical descriptions and with information summarized in annexes 2 shaped basin bounded by Mount Aragats to the north and and 3 in the Armenian Branch of Mendez England and Associ- Mount Ararat to the south. Of the two mountain peaks, the ates (2014) report. largest is Mount Ararat located in Turkey (fig. 1). The highest Well top elevations provided by ASPIRED were elevation in the Ararat Basin is in the northwest and the lowest corrected with a Landsat 30-m digital elevation model elevation is in the southeast (fig. 2). The Aras River divides (DEM), available through the USGS EarthExplorer the Ararat Basin into northern and southern regions. The (https://earthexplorer.usgs.gov) website. The hydrogeologic northern region is in Armenia and contains the study area (fig. unit thicknesses and the top and bottom elevations were then 2), which was the focus area for the hydrogeologic framework, adjusted using the corrected well top elevations. The final in part, because of the sparse well information in the southern corrected lithologic elevations were used to group the litho- region located in Turkey. In general, the thickest part of the logic descriptions and map them with nine hydrogeologic basin is in the central part of the study area, with a thickness units (fig. 3). of approximately 220 m. The shallowest part of the basin is in the southeastern part of the study area, with a thickness of approximately 15 m. The hydrogeologic framework of the Ararat Basin contains basin fill and interbedded geologic material consisting of dense clays, gravels, sands, volcanic basalts, and andesite deposits. A complete geologic history of the basin was described by the Armenian Branch of Mendez England and Associates (2014). 6 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

Table 2. Lithologic descriptions, thickness, and water-bearing potential for 24 unique lithological materials based on lithologic logs for wells drilled in the Ararat Basin, Armenia.

[Descriptions and thickness statistics were based on lithologic data provided by the Advanced Science and Partnerships for Integrated Resource Development (ASPIRED) program (Lilith Harutyunyan, ASPIRED program, written commun., 2016)]

Thickness (meters) Water bearing Lithological description 1 Maximum Minimum Mean potential Basalt with volcanic slag and sand 82 1 23.7 High. Boulder pebble deposits with clay filling 88.7 1.8 22.9 Moderate. Boulder pebble deposits with coarse-grained sand filling 93.2 4.5 29.1 High. Boulder pebble deposits with sand-clay filling 80 4 30.1 High. Clay sand 8.8 7 7.9 Low. Coarse-grained sand 49.7 6 40.1 High. Dense basalt andesite dacite 61.6 0.5 21.5 Low. Dense clay 60 0.5 8.7 Low. Fine-grained silty sand 14.6 5.8 9.3 High. Gravel 89.5 1 35.0 High. Gravel pebble deposits with clay filling 74.3 10 26.7 Moderate. Gravel pebble deposits with coarse-grained sand and 4 boulder filling 109.8 31.2 High. Gravel pebble deposits with sand-clay filling 89 6 39.3 Moderate. Gravel sand 89.5 4 38.7 High. Gypsiferous salt bearing clay with interbedded siltstone 2 marl and sandstone 2 2.0 Low. Highly fractured basalt 147.8 0.2 35.6 Moderate. Loam 56 0.3 5.3 Low. Loam sandy loam 39.2 3 19.2 Low. Poorly cemented sandstone 11 6 7.4 High. Sandy clay with interbedded sand pebbles and gravel 73 1 12.3 Moderate. Sandy loam 70 0.4 10.9 Moderate. Slags and fragments of volcanic rocks and pumice sand 75 8 24.0 High. Slightly fractured porous basalt 110 2 33.1 High. Volcanic tuff 15 8 11.3 Low. 1Interpretations were based on the generalized descriptions described in Armenian Branch of Mendez England and Associates (2014). Data and Methods 7 g h g h g h g h i i i i o w o w o w o w o w L L L L L potential Water-bearing Water-bearing Geologic units . table 1 Loam, ense clay, sany loam, clay with interbee san pebbles an grael, bouler pebble eposits Loam, ense clay, with clay filling, loam sany loam, san, an bouler pebble eposits san-clay filling ouler pebble eposits with coarse-graine san filling, grael an bouler filling, grael, pebble eposits with san-clay grael san, clay filling, slags an fragments of olcanic rocks pumice san, sany loam, grael pebble eposits with san-clay filling, ense basalt anesite acite, with olcanic slag an san, grael pebble eposits clay filling, coarse-graine san, highly fracture basalt crushe, an sany with interbee san pebbles an grael sany clay with interbee san pebbles an grael, ense basalt anesite acite, loam loam, Dense clay, sany loam, grael pebble eposits with clay filling, san-clay olcanic tuff, loam, clay san, bouler pebble eposits with filling, an highly fracture basalt crushe rael pebble eposits with coarse-graine san an bouler filling, coarse-graine san filling, highly fracture basalt crushe, grael, slags an fragments of olcanic rocks pumice san, basalt with olcanic slag an grael pebble eposits san-clay filling, bouler pebble eposits with san-clay filling, slightly fracture basalt porous, clay filling, sany clay with interbee san pebbles an grael, coarse-graine san, fine-graine silty grael pebble eposits with clay filling ense basalt anesite acite, sany clay with interbee san pebbles an grael, loam, Dense clay, clay san, loam, an bouler pebble eposits with san-clay filling olcanic tuff, ighly fracture basalt crushe, grael pebble eposits with coarse-graine san an bouler filling, pebble eposits with coarse-graine san filling, grael, bouler san-clay slightly fracture basalt porous, fine-graine silty san, with olcanic slag an slags fragments of olcanic rocks an pumice san, grael pebble eposits with san-clay filling, poorly cemente sanstone, grael pebble eposits with clay filling, an sany interbee san pebbles sany clay with interbee san pebbles an grael, loam, grael Dense basalt anesite acite, ense clay, pebble eposits with san-clay filling, an gypsiferous salt bearing clay interbee siltstone marl sanstone ighly fracture basalt crushe, slightly porous, grael pebble eposits with coarse-graine san an bouler filling, basalt with olcanic slag san, pebble eposits coarse-graine san slags an fragments of olcanic rocks pumice san, coarse-graine san an sany clay with interbee san pebbles grael Dense basalt anesite acite, ense clay, t l a s b a y y a a e c l c l t u r l t t l a a y c y s a a a c l ba s f r c l

b a l l l

l e e e e e e m y e n s n s a a a General name n s a a e r r r e l o a r e D C D L D 2 6 3 7 9 8 1 4 5 unit Hydrogeologic Hydrogeologic ydrogeologic units of the study area interpreted from lithologic logs as described in H

Figure 3. General lithology 8 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

The unique lithologic layers were consolidated into nine uppermost water-bearing gravel layer (hydrogeologic unit 2) hydrogeologic units based on lithologies and water-bearing consists of interbedded gravels; boulder pebble deposits with potential. Of the 2,500 lithologic logs provided in English, sand and clay filling; highly fractured basalts; and fragments 229 well logs were not used for the following reasons: of volcanic rocks, pumice, and sand. The total estimated 1. Lack of detail in lithologic descriptions, specifically for volume for the first water-bearing unit (hydrogeologic unit 2) the upper or lower parts of the lithologic logs. Insuffi- was 72 km3. The volumes of other water-bearing units were cient detail was determined by comparing the log to sur- 61 km3 for hydrogeologic unit 4, 38 km3 for hydrogeologic rounding well logs and comparing the well descriptions, unit 6, and 53 km3 for the lowest water-bearing unit (hydro- thicknesses, and well top elevations. geologic unit 8). The total volume of the entire basin (water- and nonwater-bearing units) was estimated as 366 km3. 2. Overlapping descriptions, specifically descriptions that included several geologic units. Overlap problems were resolved by using well logs from surrounding wells. Hydrologic Data

3. Wells with land-surface elevation discrepancies. All the A USGS team provided in-country training to Armenian wells had a reported elevation in the database, which was hydrology professionals in February–March 2016 in Yerevan, assumed to approximate the land-surface elevation and Armenia (Carter and others, 2016). Topics included ground- compared with a 30-m DEM to verify elevation accura- water modeling, well inventory, collection of water-level data, cies. In the entire lithologic database, 87 percent of the measuring well discharge, and water-quality sampling, includ- land-surface elevations that were reported differed from ing selected stable isotopes and cesium-137 for age-dating the DEM value by more than 1 m. Only about 370 wells purposes. This training included classroom-style lectures in had the same value as the DEM value. Because of the Yerevan and field training at selected sites visited in March large number of wells (87 percent) that did not match the 2016 (fig. 1). Sites included locations with flowing and non- DEM, a standard approach of removing wells that did flowing wells and surface-water features. not meet elevation requirements was applied system- atically throughout the database. A well did not meet elevation requirements if its lithologic log top elevation Groundwater Data differed by more than two standard deviations from the mean of 30-m DEM cells within a resampled 500-m grid On March 2, 2016, field measurements were made at square, which was used for interpolation. A well with a four well sites in the study area (fig. 1, table 3). Collected reported top elevation that varied more than two stan- data included location, water level, well discharge, and notes dard deviations from the mean was not included in the describing site status. Field techniques were demonstrated final database because of the uncertainty in the reported using USGS field data collection protocols (Cunningham and land-surface elevation at the well. A subset of wells was Schalk, 2011) (fig. 4). randomly selected and the well land-surface elevations In 2016, using training provided by USGS, personnel were checked with land-surface elevations derived from from Hydrogeological Monitoring Center (under contract to Google Earth Pro (© 2016 Google) for verification. the ASPIRED program) completed an inventory of wells in Lithologic descriptions from each well log were corre- the study area. Data describing well status, water levels, and lated to the nine units and assigned a depth below the land field water-quality constituents for more than 2,800 wells surface. The depths were converted to elevation and each were collected. The data were provided to personnel from well’s unit elevation was imported into a geographic informa- the ASPIRED program, who provided quality-assurance tion system (GIS). The elevation point data were used to create and project oversight on the well inventory. These data were raster surfaces using the Esri topo-to-raster interpolation tool provided by the ASPIRED program to the USGS. Data (Esri, 2017). The topo-to-raster method was chosen because collected during the well inventory are provided in table 4 as a the method optimizes the use of all the data points into a Microsoft® Excel spreadsheet as a courtesy to readers. contoured topographic grid. Thickness rasters for each of the Data collected during the well inventory for use in poten- potential water-bearing units were created with the elevation tiometric surface maps were further checked by the USGS. rasters to compare aquifer volumes across the basin. The checking process determined that the land-surface eleva- The volume of each unit was determined using a grid tions for more than 200 wells were inaccurate. These eleva- consisting of 157 rows and 232 columns and a cell size of tions were corrected using Google Earth Pro (© 2016 Google) 500 m by 500 m. The volume estimates for the water-bearing and a 30-m DEM of the Ararat Basin. Only the corrected land- units ranged from 38 to 72 cubic kilometers (km3). The surface elevation data are provided in table 4. Data and Methods 9

Table 3. Water-level and well discharge data collected in the Ararat Basin by U.S. Geological Survey in March 2016.

[Negative values for longitude indicate east of Prime Meridian. USGS, U.S. Geological Survey; WGS 84, World Geodetic System of 1984; °, degrees; ʹ, minutes; ʺ, seconds; L/s; liter per second; --, not applicable]

Notes (fig. 1) Site type USGS site Use of water above WGS 84) Discharge type Site description Water-level date Water-level seconds) (WGS 84) Well discharge (L/s) Well identification number above [-] land surface) Latitude (degrees, minutes, decimal seconds) (WGS 84) Longitude (degrees, minutes, Land-surface elevation (meters Water level (in meters below or Water

394953044375601 Well near 39°49ʹ53.3ʺ ˗44°37ʹ55ʺ 817.8 Observation Unused 03/02/2016 5.47 -- -- Had been used Yeghegnavan, for irrigation Armenia previously. number 1297

395751044322601 Well at Artashat, 39°57ʹ50.6ʺ ˗44°32ʹ26ʺ 836.7 Withdrawal Irrigation 03/02/2016 2.07 Pumped 0.17 Pumped for Armenia 10 minutes with no drawdown.

400250044235601 Well number 40°02ʹ49.9ʺ ˗44°23ʹ56ʺ 826.0 Withdrawal Waste -- -- Flowing 1.08 Flowing well 1536 near Sis, discharging Armenia onto land surface.

400347044223901 Well at Sis, 40°03ʹ47.4ʺ ˗44°22ʹ39ʺ 831.8 Withdrawal -- 03/02/2016 -2.74 Flowing 1.45 -- Armenia

A B

C Figure 4. Collection of hydrologic data on March 2, 2016, as part of field training in Armenia. A, Collection of water-level data from a nonflowing well near Ararat, Armenia (U.S. Geological Survey site 394953044375601). B, Collection of water-level data from a flowing well near Masis, Armenia (U.S. Geological Survey site 400250044235601). C, Collection of well discharge data from a nonflowing well near Artashat, Armenia (U.S. Geological Survey site 395751044322601). 10 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

Table 4. Hydrologic data provided to the U.S. Geological were measured using data collection protocols as described Survey from the 2016 well inventory conducted in the Ararat by U.S. Geological Survey (variously dated). In addition to Basin, Armenia, by Armenian partners (available online at field water-quality measurements, samples were collected https://doi.org/10.3133/sir20175163). at selected sites for analyses of stable isotopes of hydrogen and oxygen. Field water-quality measurements and results of To determine groundwater-level changes with time, laboratory analyses of samples collected by the USGS during historical water-level data were acquired from ASPIRED the field training are presented intable 7. researchers. The ASPIRED program provided a GIS file Stable isotopes of hydrogen (deuterium [2H] and protium containing water-level data from 2007 for about 1,600 wells [1H]) and oxygen (18O and 16O) are used to evaluate recharge in the Ararat Basin. The data were digitized from two reports areas and groundwater flow paths. Stable isotope values are (in Armenian) by the Institute of Water Problems and Hydrau- given in “delta notation,” which compares the ratio between lic Engineering after Academic Yeghiazarov of the Republic heavy and light isotopes of a sample to that of a reference of Armenia (2007a, 2007b). The initial construction of a standard. Delta (δ) values are expressed as a difference, in potentiometric surface map using the 2007 data indicated per mil, from value reference standard (Révész and Coplen, that land-surface elevations for more than 400 wells were 2008a). Samples for analyses of stable isotopes were collected not accurate. These elevations were corrected using Google according to USGS methods (Reston Stable Isotope Labora- Earth Pro (© 2016 Google) and a 30-m DEM of the Ararat tory, 2016). Glass bottles (60-milliliter) for stable isotope Basin. The 2007 water-level data are provided in table 5 as a samples (fig. 5) were filled two-thirds full to prevent freeze- Microsoft® Excel spreadsheet as a courtesy to readers. More thaw breakage. Bottles were then sealed with a polyseal cap. than 1,000 additional wells are included in table 5 for which Sample bottles were stored at room temperature and shipped water-level data were not collected but for which the use of to the USGS’s Reston Stable Isotope Laboratory in Reston, water was provided. Virginia, for analyses by methods described in Révész and Coplen (2008a, 2008b). Table 5. Historical water-level data from 2007 in the Ararat As part of the well inventory completed in 2016, person- Basin, Armenia, provided to the U.S. Geological Survey by nel from the Hydrogeological Monitoring Center (under Armenian partners (available online at https://doi.org/10.3133/ contract to the ASPIRED program) measured specific conduc- sir20175163). tance and temperature in well water using USGS protocols (U.S. Geological Survey, variously dated). The specific Additional historical water-level data were obtained from conductance and temperature data were included in the hydro- annex 4 in Armenian Branch of Mendez England and Associ- logical data provided to the USGS (table 4). Personnel from ates (2014). The report contained water-level data collected the Hydrogeological Monitoring Center also collected water- from 64 wells in the Ararat Basin from 1981 to 2013. The data quality data on mineralization, which represents a sum of from these 64 wells are provided in table 6 as a Microsoft® concentration of seven ions (calcium, magnesium, potassium, Excel spreadsheet as a courtesy to readers. sodium, chloride, sulfate, and bicarbonate) in a water sample. The method used for measuring mineralization is not known, Table 6. Historical water-level and well yield data from various but the data are included in table 4. dates ranging from 1981 to 2013 in the Ararat Basin, Armenia (available online at https://doi.org/10.3133/sir20175163).

Potentiometric surface maps were constructed for four Hydrogeologic Framework hydrogeologic units in the study area based on water-level data from the 2016 well inventory. Hydraulic heads were The groundwater resources and general geologic char- plotted for each of the hydrogeologic units and contoured at acteristics of the Ararat Basin are described by Armenian a 10-m interval. The contours were generalized and did not Branch of Mendez England and Associates (2014). That report strictly follow hydraulic-head data to allow for smooth contour includes groundwater trends over time and estimated flows in lines. Isolated hydraulic heads that caused “bull’s-eyes” in and out of the Ararat Basin; however, groundwater discharge the contours were ignored because they were determined to into rivers was not measured and discharge numbers remain be either within the margin of error for the contour interval unknown. It is clear, however, that the groundwater discharge or they were assumed to be based on incorrect water-level component is an important part of groundwater balance measurements. because the Metsamor River, for example, is recharged (fed) exclusively by groundwater. In 2016, a well inventory was Water-Quality Data completed by the Armenian Branch of Mendez England and Associates to further define and characterize the hydrogeol- On March 2, 2016, four wells and one stream site in the ogy in and around the Ararat Basin. The inventory included Ararat Basin were measured for field water-quality constitu- approximately 2,800 wells completed in and around the Ararat ents (fig. 1). Water temperature and specific conductance Basin. The inventory’s goal was to further characterize the Hydrogeologic Framework 11

Table 7. Water-quality data collected or analyzed by U.S. Geological Survey in March 2016 in the Ararat Basin, Armenia.

[Negative values for longitude indicate east of Prime Meridian. USGS, U.S. Geological Survey; WGS 84, World Geodetic System of 1984; °, degrees; ʹ, minutes; ʺ, seconds; µS/cm; microsiemens per centimeter; δ2H, stable isotope ratio of hydrogen-2 to hydrogen-1; δ18O stable isotope ratio of oxygen-18 to oxygen-16; --, not applicable]

Latitude Longitude (degrees, Specific Water tem- USGS site (degrees, Sample minutes, conduc- perature δ2H δ18O identification Site description minutes, collection decimal tance (degrees (per mil) (per mil) number seconds) date seconds) (µS/cm) Celsius) (WGS 84) (WGS 84) 394953044375601 Well near Yeghegnavan, 39°49ʹ53.3ʺ -44°37ʹ55ʺ 03/02/2016 615 15.6 ˗72.70 -10.84 Armenia number 1297 395751044322601 Well at Artashat, Armenia 39°57ʹ50.6ʺ -44°32ʹ26ʺ 03/02/2016 1,440 15.2 ˗70.00 -10.46 400250044235601 Well number 1536 near 40°02ʹ49.9ʺ -44°23ʹ56ʺ 03/02/2016 841 16.9 ˗69.50 -10.33 Sis, Armenia 400347044223901 Well at Sis, Armenia 40°03ʹ47.4ʺ -44°22ʹ39ʺ 03/02/2016 692 15.2 ˗70.90 -10.68 401110044295401 Hrazdan River at 40°11ʹ10.0ʺ -44°29ʹ54ʺ´ 03/02/2016 -- -- ˗71.60 -10.58 Yerevan, Armenia

lithology, water levels, and additional hydrologic properties. The 2016 well inventory was used to supplement and update previously published groundwater data. Additionally, the 2016 inventory permitted calculation of groundwater trends and aquifer response to stresses. These stresses could include pumping, climatic variations, and changes in water use and land use in the Ararat Basin. This section describes in more detail the Ararat Basin lithology of the area, the various hydrogeologic units, and the areal extent of the basin.

Areal Extent

The Ararat Basin is in southern Armenia and northern parts of Turkey (fig. 1). The basin is a depression valley filled with a complex geologic network of buried ancient river channels covered by volcanic tuff and basalts. Additionally, modern alluvial deposits from several rivers in the basin, including the Aras River and its tributaries (Armenian Branch of Mendez England and Associates, 2014), fill the basin. The northern region of the Ararat Basin in Armenia extends north of the Aras River. The basin’s area is about 1,300 km2 with elevations ranging from 800 to 1,000 m above sea level (Armenian Branch of Mendez England and Associates, 2014). The basin is approximately 110 kilometers (km) from west to east and from about 5 to 30 km north to south (fig. 1).

Figure 5. Collection of stable-isotope sample from a flowing well (U.S. Geological Survey site 400250044235601) in the Ararat Basin, Armenia. 12 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

Hydrogeologic Units with coarse-grained sand and boulder filling, and gravels. About 42 percent of the hydrogeologic unit is boulder pebble The Ararat Basin surficial geology is dominated by deposits. Gravel pebble deposits with coarse-grained sand alluvial deposits overlying several water and nonwater-bearing and boulder filling and gravels make up the other 38 percent units. The Armenian Branch of Mendez England and Associ- (28 percent and 10 percent, respectively). The remaining ates (2014) published an extensive study of the groundwater geologic material includes basalt with volcanic slag and and descriptions of several hydrogeologic formations that sand (1 percent), boulder pebble deposits with clay filling make up the Ararat Basin. USAID, in cooperation with the (3 percent), boulder pebble deposits with sand-clay filling Armenian Branch of Mendez England and Associates (2014), (7 percent), dense basalt andesite dacite (1 percent), gravel described a hydrogeology of complex inner layering of pebble deposits with clay filling (1 percent), gravel pebble sandstones and igneous rock types (fig. 3). From these sources deposits with sand-clay filling (1 percent), gravel sand and recent well lithological information, nine hydrogeologic (3 percent), sandy loam (1 percent), and slags and fragments units were identified in the Ararat Basin study area fig.( 6). of volcanic rocks and pumice sand (2 percent). Lithologic The study area was divided into three subregions (Western, logs from 2,483 wells were used to define unit 2 fig.( 8). Central, and Eastern) for purposes of describing the lithology, Spatially, the wells covered most of the study area with the thicknesses, and density of wells that defined the units fig.( 7). higher density of wells in the south central part of the basin The subregions were separated using rivers that flowed north (fig. 7). Unit 2 had the greatest number of wells drilled into the to south. The subregions (fig. 7), nine hydrogeologic units, unit compared to other units (table 8). Unit 2 was the thickest and lithologic characteristics and descriptions (fig. 3) that unit with a mean thickness of 32 m. The maximum measured constitute each of the units are described in the following thickness, determined from lithologic logs, was 89 m. Unit 2 subsections. was the thinnest measured and interpolated water-bearing unit (table 8). The maximum interpolated thickness was 84 m. The thickest part of the unit, based on the interpolated values, was Hydrogeologic Unit 1 in the western and central subregion where most of the wells drilled into the unit were located (figs. 7, 9). The uppermost hydrogeologic unit (unit 1) consists primarily of loam, dense clay, and sandy loam. The unit is characterized mostly by loam, which makes up about Hydrogeologic Unit 3 66 percent of the geologic unit. Sandy loam and a dense clay layer make up the other 25 percent (12 percent and Unit 3 underlies unit 2 and is a nonwater-bearing unit 13 percent, respectively). The remaining geologic material (confining layer). It consists of dense clay, sandy clay with interbedded sand pebbles and gravel, and dense basalt andesite includes boulder pebble deposits with clay filling (1 percent), dacite. The unit was characterized mostly by dense clays that loam sandy loam (1 percent), and sand and fragments of constitute about 69 percent of the geologic unit. Sandy clay volcanic rocks and pumice sand (7 percent). Lithologic logs with interbedded sand pebbles and gravel and dense basalt from 2,301 wells were used to define unit 1, and spatially andesite dacite make up the other 18 percent (11 percent these wells covered most of the study area (fig. 8). Unit 1 had and 7 percent, respectively). The remaining geologic mate- the third highest number of wells drilled into the unit when rial includes boulder pebble deposits with clay filling compared to all other unit descriptions and lithologic logs (1 percent), clay sand (1 percent), gravel pebble deposits with (table 8). Unit 1 was the thinnest when compared to the other 8 clay filling (1 percent), gravel pebble deposits with sand- units, with a mean thickness of 8 m. The maximum measured clay filling (1 percent), highly fractured basalt (1 percent), thickness, determined from lithologic logs, was 51 m. The loam (1 percent), loam sandy loam (4 percent), sandy loam maximum interpolated thickness was 84 m. The interpolated (2 percent), and volcanic tuff (3 percent). Lithologic logs from thickness is higher along the unit’s northern border because it 2,242 wells were used to define unit 3 fig.( 8) and spatially includes topographically high areas along the perimeter of the these wells covered most of the basin, with a higher density study area and few lithologic logs (fig. 9). of wells in the south-central part of the basin (fig. 7). Unit 3 ranked fourth in the total number of wells drilled into the unit Hydrogeologic Unit 2 (table 8). The mean thickness of the unit was 14 m and the maximum measured thickness, determined from lithologic Underlying unit 1 is the uppermost water-bearing logs, was 62 m. The maximum interpolated thickness was unit, unit 2, consisting primarily of boulder pebble depos- 83 m (table 8). The thickest part of the unit, based on the inter- its with coarse-grained sand filling, gravel pebble deposits polated values, was in the western subregion (figs. 7, 9).

Hydrogeologic Framework 13

A ' 1984 of System Geodetic World B Elevation, in meters above meters in Elevation, 1,000 800 600 IRAN B ' EST ARMENIA Ararat Valley TURKEY , tilted side profile view from north S E Study area R S C L I E T ’; B ′ E A M 15 M L A I to A 10 15 K 0 1 SUTHEAST 5 5 0 0 VERTICAL EAGGERATIN 50 VERTICAL EAGGERATIN B

SUTHEAST

700 500 900

World Geodetic System of 1984 of System Geodetic World Elevation, in meters above meters in Elevation, , tilted side profile view from south along C B S

World Geodetic System of 1984 of System Geodetic World 15 M above meters in Elevation, EAST R S E T E M 1,000 800 600 L I 10 A ' A ' 15 K SUTHEAST 0 1 5 VERTICAL EAGGERATIN 50 VERTICAL EAGGERATIN 5 0 0 S E R S L I E T E M 15 M L I 10 15 K 0 1 5 5 , three-dimensional tilted view of study area from above; 0 0 A VERTICAL EAGGERATIN 50 VERTICAL EAGGERATIN . Line of side profile view EPLANATION A ' 1 2 3 4 5 6 7 8 9 ’. Three-dimensional special interpretation of the Ararat Basin, Armenia, derived from lithologic logs provided by Advanced S cience and Partnerships for Integrated A B A Hydrogeologic unit (fig. 3) EST

A EST to 800 600

1,000

World Geodetic System of 1984 of System Geodetic World Elevation, in meters above meters in Elevation, B Figure 6. Resource Development group along 14 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

C N

WESTERN CENTRAL ARMENIA A A'

EASTERN EPLANATION Hydrogeologic unit (fig. 3) TURKEY 1 2 EPLANATION 3 Study area 4 5 River segment 6 7 Base from U.S. Geological Survey Shuttle 8 Radar Topography Mission 0 5 10 15 KILMETERS C' 9 orld Geodetic System of 184 proection, IRAN eb Mercator Auxiliary Sphere 0 5 10 15 MILES A A' Line of side profile view

A A' 1,000 1,000

900 900

800 800 Elevation, in meters above

World Geodetic System of 1984 World 700 VERTICAL EAGGERATIN 50 700

0 5 10 KILMETERS B B' 1,000 0 5 10 MILES 1,000

900 900

800 800 Elevation, in meters above

World Geodetic System of 1984 World 700 700 VERTICAL EAGGERATIN 50 0 5 10 KILMETERS C C' 1,000 1,000 0 5 10 MILES

900 900

800 800

700 700 Elevation, in meters above

World Geodetic System of 1984 World 600 VERTICAL EAGGERATIN 50 0 5 10 KILMETERS 600

0 5 10 MILES

Figure 7. Map of three subbasin areas and three cross sections of the Ararat Basin, Armenia, used to define the nine hydrogeologic units. Hydrogeologic Framework 15

Unit 1 Unit 2 Unit 3 ARMENIA ARMENIA ARMENIA

TURKEY TURKEY TURKEY

Number of wells: 2,301 IRAN Number of wells: 2,483 IRAN Number of wells: 2,242 IRAN

Unit 4 Unit 5 Unit 6 ARMENIA ARMENIA ARMENIA

TURKEY TURKEY TURKEY

Number of wells: 2,348 IRAN Number of wells: 1,462 IRAN Number of wells: 1,378 IRAN

Unit 7 Unit 8 Unit 9 ARMENIA ARMENIA ARMENIA

TURKEY TURKEY TURKEY

Number of wells: 875 IRAN Number of wells: 832 IRAN Number of wells: 166 IRAN

Base from U.S. Geological Survey 0 25 50 KILMETERS EPLANATION orld Geodetic System of 184 proection, eb Mercator Auxiliary Sphere Thickness (meters) 0 25 50 MILES 1 to 10 71 to 80 11 to 20 81 to 90 21 to 30 91 to 100 31 to 40 101 to 110 41 to 50 111 to 120 51 to 60 121 to 130 61 to 70 Well location

Figure 8. Number and distribution of wells used to generate thicknesses for each of the nine hydrogeologic units in the Ararat Basin, Armenia. 16 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

Unit 1 Unit 2 Unit 3 ARMENIA ARMENIA ARMENIA

TURKEY TURKEY TURKEY

Maximum: 84 meters (m) IRAN Maximum: 84 m IRAN Maximum: 83 m IRAN

Unit 4 Unit 5 Unit 6 ARMENIA ARMENIA ARMENIA

TURKEY TURKEY TURKEY

Maximum: 103 m IRAN Maximum: 80 m IRAN Maximum: 111 m IRAN

Unit 7 Unit 8 Unit 9 ARMENIA ARMENIA ARMENIA

TURKEY TURKEY TURKEY

Maximum: 124 m IRAN Maximum: 106 m IRAN Maximum: 92 m IRAN

Figure 9. Thickness of all nine hydrogeologic units in the Ararat Basin, Armenia. Hydrogeologic Framework 17

Table 8. Summary of each unit detailing the number of wells used in defining the geologic material, the average unit thickness across the Ararat Basin, and the maximum measured and interpolated thicknesses within each of the hydrogeologic units.

Average unit Maximum measured Maximum interpolated Number of wells Unit number Primary geological material thickness thickness within unit thickness within unit drilled into the unit (meters) (meters) (meters) 1 Loam 2,301 8 51 84 2 Boulder pebble deposits 2,483 32 89 84 3 Dense clay 2,242 14 62 83 4 Gravel pebble deposits with 2,348 27 110 103 coarse-grained sand and boulder filling 5 Dense clay 1,462 9 73 80 6 Highly fractured basalt 1,378 17 148 111 7 Dense basalt andesite dacite 875 10 60 124 8 Highly fractured basalt 832 23 119 106 9 Dense basalt andesite dacite 166 22 68 92

Hydrogeologic Unit 4 Hydrogeologic Unit 5 Unit 4 underlies unit 3 and is the second water-bearing Underlying unit 4 is a nonwater-bearing unit (confin- unit. Unit 4 consists primarily of gravel pebble deposits ing layer), unit 5, consisting primarily of dense clay, dense with coarse-grained sand and boulder filling, boulder pebble basalt andesite dacite, and sandy clay with interbedded sand deposits with coarse-grained sand filling, and gravel. The pebbles and gravel. The unit is characterized by dense clay, unit is characterized mostly by gravel pebble deposits with which makes up about 68 percent of the geologic unit. Dense coarse-grained sand and boulder filling, which make up basalt andesite dacite and sandy clay with interbedded sand about 35 percent of the geologic unit. Boulder pebble depos- pebbles and gravel make up the other 23 percent (12 percent its with coarse-grained sand filling and gravel make up the and 11 percent, respectively). The remaining geologic mate- other 41 percent (34 percent and 7 percent, respectively). The rial includes clay sand (1 percent), sandy loam (4 percent), remaining geologic material includes basalt with volcanic and volcanic tuff (3 percent). Lithologic logs from 1,462 wells slag and sand (3 percent), boulder pebble deposits with clay were used to define unit 5 fig.( 8). The western part of the filling (1 percent), boulder pebble deposits with sand-clay study area had few lithologic logs available to define the filling (2 percent), gravel pebble deposits with sand-clay filling geologic unit (fig. 7). The south-central and eastern subre- (2 percent), gravel sand (3 percent), highly fractured basalt gions of the study area have a higher density of wells than (9 percent), sandy clay with interbedded sand pebbles and the western subregion (fig. 8). Unit 5 ranked fifth in the total gravel (1 percent), slags and fragments of volcanic rocks and number of wells drilled into the unit in the study area (table 8). pumice sand (3 percent), and slightly fractured porous basalt The mean thickness of the unit was 9 m (the second thinnest (1 percent). Lithologic logs from 2,348 wells were used to unit). The maximum measured thickness, determined from define unit 4 fig.( 8; table 8) and spatially these wells covered lithologic logs, was 73 m. The maximum interpolated thick- most of the basin with a higher density of wells in the south- ness was 80 m (table 8). The thickest part of this unit, based central part of the basin (fig. 7). Unit 4 had the second largest on the interpolated values, was in the central and western number of wells drilled into the unit (table 8). The mean thick- subregions of the basin (figs. 7, 9). ness of the entire unit was 27 m and the maximum measured thickness, determined from lithologic logs, was 110 m. The maximum interpolated thickness was 103 m (table 8). The thickest part of the unit, based on the interpolated values, was in the central and eastern subregions of the basin (figs. 7, 9). 18 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

Hydrogeologic Unit 6 the measured thickness likely because it includes topographically high areas along the perimeter of the basin and because Underlying unit 5 is the third water-bearing unit, unit 6, of the limited spatial distribution of available lithologic which consists primarily of highly fractured basalt, gravel information. pebble deposits with coarse-grained sand and boulder filling, and boulder pebble deposits with coarse-grained sand filling. The unit is characterized mostly by highly fractured basalt, Hydrogeologic Unit 8 which makes up about 43 percent of the geologic unit. Gravel pebble deposits with coarse-grained sand and boulder filling Underlying unit 7 is the fourth water-bearing unit, unit and boulder pebble deposits with coarse-grained sand filling 8, which consists primarily of highly fractured basalt, slightly make up the other 21 percent (12 percent and 9 percent, fractured porous basalt, and gravel pebble deposits with respectively). The remaining geologic material includes coarse-grained sand and boulder filling. The unit is character- basalt with volcanic slag and sand (5 percent), boulder pebble ized mostly by highly fractured basalt, which makes up about deposits with sand-clay filling (7 percent), fine-grained silty 68 percent of the geologic unit. Slightly fractured porous sand (6 percent), gravel (9 percent), gravel pebble deposits basalt and gravel pebble deposits with coarse-grained sand with sand-clay filling (1 percent), gravel sand (1 percent), and boulder filling make up the other 19 percent (13 percent poorly cemented sandstone (1 percent), slags and fragments and 6 percent, respectively). The remaining geologic mate- of volcanic rocks and pumice sand (1 percent), and slightly rial included basalts with volcanic slag and sand (5 percent), fractured porous basalt (6 percent). Lithologic logs from boulder pebble deposits with coarse-grained sand filling 1,378 wells were used to define unit 6 fig.( 8). There were few (4 percent), and slags and fragments of volcanic rocks and lithologic logs in the southwestern part of the study area avail- pumice sand (4 percent). Lithologic logs from 832 wells were able to define the geologic unit. More wells were available in used to define unit 8 fig.( 8). The western and eastern subre- the southern part of the central subregion and in the eastern gions of the study area had few available lithologic logs. There subregion of the basin (fig. 7). Unit 6 ranked sixth in the were more logs available in the southern part of the central total number of wells drilled into the unit (table 8). The mean subregion (fig. 7). Unit 8 ranked eighth in the total number of thickness of the unit was 17 m and the maximum measured wells drilled into the unit (table 8). One potential reason for thickness, determined from lithologic logs, was 148 m. The the lack of lithologic information for unit 8 could be high drill- maximum interpolated thickness was 111 m (table 8). The ing costs required to complete a well in unit 8 because of large thickest part of the unit, based on the interpolated values, was depths (fig. 7). The mean thickness of the unit was 23 m and in the south-central part of the central subregion and northern the maximum measured thickness, determined from lithologic part of the eastern subregion (figs. 7, 9). logs, was 119 m. The maximum interpolated thickness was 106 m (table 8). The thickest part of the unit, based on the Hydrogeologic Unit 7 interpolated values, was in the central subregion of the basin (figs. 7, 9). Underlying unit 6 is a nonwater-bearing unit (confining layer), unit 7, which consists primarily of dense basalt andesite dacite, dense clay, and sandy clay with interbedded Hydrogeologic Unit 9 sand pebbles and gravel. The unit is characterized mostly by Underlying unit 8 is a nonwater-bearing unit (confin- dense basalt andesite dacite, which makes up about 48 percent ing layer) and the framework’s deepest unit, unit 9, which of the geologic unit. Dense clay and sandy clay with interbed- consists primarily of dense basalt andesite dacite, dense clay, ded sand pebbles and gravel made up the other 49 percent and sandy clay with interbedded sand pebbles and gravel. (37 percent and 12 percent, respectively). The remaining geologic material included gravel pebble deposits with sand- The unit was characterized mostly by dense basalt andesite clay filling (1 percent) and loam (1 percent). Lithologic logs dacite, which makes up about 46 percent of the geologic unit. from 875 wells were used to define unit 7 fig.( 8). Although Dense clay and sandy clay with interbedded sand pebbles and fewer wells were used to define the unit than the six previ- gravel made up another 53 percent, 43 percent, and 10 percent, ously described units, spatially the wells covered most of the respectively. Lithologic logs from 166 wells were used to study area. The central subregion had the higher density of define unit 9 (fig. 8). Unit 9 had the least number of available wells than the other subregions (fig. 7). Unit 7 ranked seventh wells. However, spatially these wells covered the majority of in the total number of wells drilled into the unit (table 8). The the study area with the highest concentration of wells located mean thickness of the entire unit was 10 m and the maximum in the basin’s center (fig. 7). The mean thickness of the unit measured thickness, determined from lithologic logs, was was 22 m thick and the maximum measured thickness, deter- 60 m. The maximum interpolated thickness was 124 m mined from lithologic logs, was 68 m. The unit’s maximum (table 8). The thickest part of the unit, based on the interpo- interpolated thickness was 92 m (table 8). The thickest part of lated values, was in the eastern subregion of the basin (fig. 9). the unit, based on the interpolated values, was in the central The maximum interpolated thickness of unit 7 is greater than subregion (figs. 7, 9). Groundwater Conditions 19

Groundwater Conditions development and growth of the aquaculture industry for the purposes of raising trout, sturgeon, and other cold water fish This section describes flowing and nonflowing aquifer (Carter and others, 2016). The artesian conditions, gener- conditions, potentiometric surfaces, changes in groundwater ally high water quality, and cool water temperatures enabled levels and well discharge over time, water use, and water aquaculture industries to thrive; however, the flowing wells quality of the northern Ararat Basin. In the Ararat Basin, the reduced the artesian pressure in the aquifer. As a result, many complex geology and hydrologic setting allows for as many wells that were flowing have ceased to flow (Armenian Branch as nine hydrogeologic units (fig. 3; table 8), which spatially of Mendez England and Associates, 2014; Carter and others, can vary as the geology changes across the basin. As described 2016). The changing pressure boundary (defined as the bound- previously in the “Hydrogeologic Units” section, four water- ary between the flowing and nonflowing wells) is also shown bearing units were identified using lithologic descriptions for in figure 10. The boundary has migrated south and decreased wells drilled in the northern region of the Ararat Basin (in in area since 1984 as described further in the “Changes in Armenia) (table 1) and were summarized by Armenian Branch Groundwater Levels and Well Discharge” section. of Mendez England and Associates (2014) in annex 2 of that report. The complexity of these units are, in part, due to the Potentiometric Surface confining units that make up the stratigraphy in the study area. Two primary aquifers were identified by the Armenian Branch Data collected during the 2016 well inventory were used of Mendez England and Associates (2014): an unconfined to construct potentiometric surface maps of the four water- aquifer (equivalent to hydrogeologic unit 2 of this report) and bearing units in the study area. No information on screened a confined aquifer (equivalent to hydrogeologic units 4, 6, interval was available; therefore, it was assumed that the unit and 8 of this report). The unconfined aquifer (hydrogeologic coincident with the well’s bottom depth contained the well unit 2) is a shallow aquifer, consisting of a sandy loam and screen. The elevation of the well bottom was compared to the gravel pebble deposits, typically ranging from 0.5 to 60 m in elevations of the tops and bottoms of the four water-bearing depth. The general direction of flow in the unconfined aquifer hydrogeologic units (units 2, 4, 6, and 8). Then, the well was is towards the Aras River (Armenian Branch of Mendez assigned a unit based on its completion depth. The locations of England and Associates, 2014). The deeper confined aquifer the 2016 inventory wells and the assigned hydrogeologic unit identified by Armenian Branch of Mendez England and Asso- for each well are shown in figure 11. ciates (2014) and subdivided in this report into water-bearing Potentiometric surface maps were generated using GIS units 4, 6, and 8 is overlain by a clay layer (unit 1) approxi- software for each of the four water-bearing hydrogeologic mately 1 to 51 m thick in some areas of the northern part of units (figs. 12–15). The potentiometric surface for hydrogeo- the basin (table 8; fig. 9), with additional confining clay layers logic unit 2 (fig. 12) had few available water-level measure- (units 3, 5, and 7) between the water-bearing units (table 8). ments because the focus of the 2016 well inventory was on The entire confined aquifer is under artesian conditions and is the confined aquifer and not the unconfined aquifer (Lilith further characterized in the central parts of the Ararat Basin Harutyunyan, ASPIRED program, oral commun., 2017). The where the confined aquifer is under flowing artesian condi- direction of groundwater flow in hydrogeologic units 2, 4, 6, tions, as described in the “Flowing and Nonflowing Aquifer and 8 was estimated based on flow paths drawn perpendicular Conditions” section. to potentiometric contours. Hydrogeologic unit 2 is the shallowest aquifer and is Flowing and Nonflowing Aquifer Conditions considered a surficial aquifer. For hydrogeologic unit 2, the estimated direction of groundwater flow is from the west to Data obtained during the 2016 well inventory (table 4) north in the western part of the study area (away from the were used to generate a map of the nonflowing and flowing Aras River) and from west to east and north to south (toward wells in the study area (fig. 10). The nonflowing aquifer the Aras River) in the eastern part of the study area. The flow conditions were on the edges of the Ararat Basin where the paths indicate that the Aras River is a losing stream (discharg- basin depth becomes shallower (Armenian Branch of Mendez ing to groundwater) in the western part of the basin; however, England and Associates, 2014). The nonflowing wells include it is gaining (groundwater is discharging to the river) in the wells completed in (1) the unconfined aquifer consisting eastern part of the basin. primarily of sandy loam and gravel pebble deposits (unit 2), In hydrogeologic unit 4, the general direction of and (2) the confined aquifer (units 4, 6, and 8) but with insuf- groundwater flow is generally from west to east and north to ficient pressure for the water level to rise above land surface. south (toward the Aras River); however, groundwater flow is The flowing artesian wells were primarily in the central northwesterly in the northwestern part of the study area (fig. part of the study area (fig. 10). These flowing artesian 13). Hydrogeologic unit 6 has this same general pattern of wells were the primary source of water that sustained the groundwater flow (fig. 14) as hydrogeologic unit 4. 20 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia 4450E

Study area 2016 Pressure boundary 2007 Pressure boundary 1984 Pressure boundary Nonflowing well Flowing well

EPLANATION

e v

4440E R

e V

Aras River Azat River Azat

4430E

v i

r H 15 MILES 4420E 10

15 KILMETERS Kasakh River Kasakh 10 5 5 4410E 0

0 Mission Base from U.S. Geological Survey Shuttle Radar Topography Mercator Auxiliary Sphere Geodetic System of 184 proection, eb orld Metsamor River Metsamor

Aras River IRAN ARMENIA 4400E . (Pressure boundary for 1984 from Armenian Branch of Mendez England and Associates, 2014; pressure 2007 based on data Study area TURKEY .) ocation of flowing and nonflowing wells in 2016 locations the 1984, 2007, pressure boundaries between non-flowing study table 5 L 4350E

4020N 4010N 4000N 350N 340N Figure 10. area of the Ararat Basin in Armenia presented in Groundwater Conditions 21 Study area in unit 2 Well in unit 4 Well in unit 6 Well in unit 8 Well EPLANATION

4450E

4440E i

z A Aras River 4430E

Hrazdan River 20 MILES 4420E

20 KILMETERS River Kasakh 10 10

4410E River

0 0 Base from U.S. Geological Survey Shuttle Radar Topography Mission Base from U.S. Geological Survey Shuttle Radar Topography Geodetic System of 184 proection, orld Mercator Auxiliary Sphere eb Aras River Aras IRAN 4400E

Metsamor ARMENIA Study area 4350E TURKEY ocation of wells included in the 2016 well inventory by hydrogeologic unit study area Ararat Basin Armenia. L

4020N 4010N 4000N 350N 340N Figure 11. 22 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

43°50’E 44°00’E 44°10’E 44°20’E 44°30’E 44°40’E 44°50’E

Kasakh River

82 86.6 40°10’N 86 r Hrazdan Rive 840 88 82 86 848.2 840 842 846. 84.8 84 Metsamor River 84 842 844.

870 84 880 8 88 850

86 860 88. 862. 86 860 8. 88.2 84 850 8. 8. 86. 8.8 862 840 82. 860 86. 86.2 8 8 Azat River 86 870 84. Aras River 8. 882 860 86.6 850 84 40°00’N 8.2 84. 82 844.8 88 8. 84 8 84 840 86 8. 82 886 Aras River 830

82. 8.6 820 8.4 880 888.8 810 8. 860

850

840

er iv R i d 830 e

39°50’N ARMENIA 820 84.

tudy area AA tudy area

860 otentiometric contourhos eleation at hich ater ould hae stood in tightly cased nonuming ells in 26. ontour interal meters. ashed here inferred. atum is orld 810 eodetic ystem of 84 86. TURKEY stimated direction of groundwater flow 86 ell for which water leel was measured in 21umer is IRAN aterleel eleation of hydraulic head in meters aoe orld eodetic ystem of 84 tale 4

Base from U.S. Geological Survey Shuttle Radar Topography Mission 0 5 10 15 20 KILOMETERS World Geodetic System of 1984 projection, Web Mercator Auxiliary Sphere 0 5 10 15 20 MILES

Figure 12. Potentiometric surface of hydrogeologic unit 2 in the study area of the Ararat Basin in Armenia. Groundwater Conditions 23

43°50’E 44°00’E 44°10’E 44°20’E 44°30’E 44°40’E 44°50’E

86 870 880 864 842 86 6 840 8 888 Kasakh River 864 88 870 8 88 8 88 84 86 84 844 860 84 8 86.4 84 84 8 870 8 88 886 850 88 844 84. 84 830 8 86. 8 8 840 84.2850 86. 8 8 8 88 8 86.8 8.2 846 8 84 84 8 8 8.2 842 8 82 8 842. 8 8. 84. 86 40°10’N 844. 8. 848 888 84.6 84 88 842 84. 8 8. 84. er 8 88 84 846 84 84. Hrazdan Riv 84 84 8.6 8 8 82 88 8 84 84 8 84. 828.6 8 86 84 822 8. 844. 84 82 82 8 82.2 82 84 8 82 8 82 84 84. 82 8 84 8 844.2 86.8 88 8 846 8 8 844. 84 842 84.2 88.4 86 8.68 M 84 8 8 84. 842.2 8. etsamor Rive 844.66 8 84 84. 86 8 8. 84 r 8 82 8.8 8.4 8.2 844 8 8. 8. 8.62 8 8.6 862 82 84 8. 8 8.6 8. 84 850 8 8 84 86.8 86.8 8 884 84.2 8 84. 8 84. 844.4 82 84. 8.4 840 84 88 844.8 8. 84.6 846.8 84. 84.8 860 8 84 8 8.8 86.8 82. 870 8. 84.2 842. 840 850 2 8. 8.2 88.2 8 8 884 84. 84 84. 8. 842 86.2 8.8 8 8 88 84 8 88. 8 8 84.2 8.4 8 8. 84 84 844. 84. 8 8 8 880 8 8 84 84. 8 86.4 8. 84. 4 8 8 84. 86 8 8 88 86.46 844. 864 848. 84. 8. 84 8.8 84.4 850 84 86 86 8. 8.6 88.4 84. 848. 86 88. 88. 84. 8 88 8.8 86.8 86. 842.2 82 848 84.2 86 8.4 86 8.8 88. 8. 4 8.2 88. 84.8 8.8 8 88 4 86 82. 8 84.8 8. 8.8 8.8 8 84. 8.4 86 88 84.6 8.6 8 86 86 8.2 86.6 88 82. 82. 86 8.8 8.6 86 8 8. 84 84 86 830 8. 860 8. 88.8 84.8 848.2 84.4 88.8 88 84. 8 84. 8.2 8 84 826 828. 8. 84 868 86. 88. 8 8 82. 846.4 826. 84 84.6 8. 8. 842 82. 84.6 8 86 86.8 8. 82 8 84.8 86. 8 86 84. 82 84. 842. 844.2 82. 86 8 8.6 84 842.6 Azat River 8 862 82. 86. 82.8 8.8 84.4 84 862 84.2 842.6 8 88. Aras River 8 84. 86 86.2 86.8 84 860 40°00’N 84. 844 84. 850 82. 8 8 840 84 82 830 84 82 8 88.6 8. 82. 88 Aras River 82.2 82. 82.2 8.6

826 880 870 890 4.2

840 850 860 8.4 82 8 . 826 824 844 .8 82 822 8 84 822 8 82.8 88. 82 82 868. 88 82 868. 8 8 82 8 r ive R di e 8. V

840

82 820 39°50’N ARMENIA 8.6 820 8. 8 AA 88.6 tudy area tudy area 8 850 otentiometric contourhos eleation at hich ater ould hae stood in tightly cased nonuming ells in 26. ontour 810 interal meters. ashed here inferred. atum is orld eodetic ystem of 84

82.2 TURKEY stimated direction of groundwater flow 88. 862 ell for which water leel was measured in 21umer is 82.8 aterleel eleation of hydraulic head in meters aoe 8. IRAN orld eodetic ystem of 84 tale 4. n areas of high ell density not all aterleel alues are shon

Base from U.S. Geological Survey Shuttle Radar Topography Mission 0 5 10 15 20 KILOMETERS World Geodetic System of 1984 projection, Web Mercator Auxiliary Sphere 0 5 10 15 20 MILES

Figure 13. Potentiometric surface of hydrogeologic unit 4 in the study area in the Ararat Basin in Armenia. 24 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

43°50’E 44°00’E 44°10’E 44°20’E 44°30’E 44°40’E 44°50’E

8 86 82 8. 840 88 Kasakh River 850 86 84 8 848. 84. 8 842 884 884 88 8 88 86 88 8 842 886 86. 848 8 88 844 844. 886 8 8 8 8 8 8.8 88 8 850 830 8 8 848. 84.6 82 86 8 842. 86 84. 82 84 868 84 88 40°10’N 88 8.2 8.6 82 842.8 8.6 82 84. 846 82. 82 84.8 r 86.8 830 830 84. 88.8 z ve 8.8 8 8 84. 84 8.8 826 88 8 86 844 84 Hra dan Ri 84 824 86. 84. 828 88 84.8 844 8.8 84 86.2 82. 840 88 828 8 84 82.8 84. 84. 8. 8. 82 8 88. 82.6 844.6 8.8 844.8 84.8 84. 86 84. 8 82 824. 8 86 84. 8. 84. 88.2 860 8 84. 844.8 8 848.4 84. 82.8 8. 84 86 8. 84. 846 84 850 M m 844.64 8 84.8 8. 82 etsa or 8.4 82 84. 844 84 8 848 R 844.4 8 84 84 8 iv 826 8 84 84 86 86.8 844 848 82 84 8. er 8 84.2 84 8 848 84 8. 84 88. 84.28 84. 84 848 84 84.2 8. 8.6 82.2 860 84 842 8 84.8 8 86.82 846 8 84.8 8.6 84. 84 84 84.2 82 84 842 84 8. 88.4 8.4 848.8 844 8. 84. 84 84 870 84 84. 84 84 84. 84.68 84.4 84. 846 844 8 84.4 88. 8 88. 82 844 8.4 84.64 848 86 84 84 846 84 84 8 844 82. 846 84 86. 86. 8. 84. 848. 8. 8. 842. 844 84.6 8. 88 8 8. 8 84 84 8 8 8.4 846.8 8 86 8 84 862 848 88 84 86. 8. 8.2 8 8 84 86 846 82 842.4 84. 8. 84. 8 84.8 8. 88 84. 86 86. 82. 824 84 8 8 8. 8.4 8. 8. 86.6 8 8 842 84.84 86.6 82 8 8 8 82 84 8 8 88.2 8.2 86.4 86. 850 88. 8. 84 84 88 8. 8. 8 4 88 8 8 82 828. 86 840 8. 8.2 8. 8.6 8. 86 8 8 86 84. 86.4 84. 86 86. 2 86 8 8 8484.2 88 8 8.6 84.4 86. 84 846 84 8. 88. 868 8 84. 84 8. 84 82 84 870 2 8. 848 8 8.2 8 8. 88 84 848 8. 84 8.2 8.4 86.2 8.6 84. 84 8. 8 8 8. 82. 84 8 8 86 8. 84.2 82 82 8.6 860 8. 8 88.4 8 8 8 82.2 86 8.4 828 866 88 84 8.6 8.2 88 86 8. 8.2 8 8 828. 82 880 82. 826. 82. 86.6 828. 82. 82 84 82. 86. 828.6 82.6 r 82. 86.2 e 850 8.8 8.2 822.8 8. v Aras River 8 i 828.6 8 R 826.6 828.8 82.6 82.4 86. t 8.8 82.4 824.6 za 840 828.2 82.4 82. A 40°00’N 826.4 8 84. 8.2 82 82 84 860 8. 844. 86 84 84 8.8 8.4 86.4 86.8 826. 86.6 84 828. 82 824 8.88 8. 8 Aras River 822. 8 82 84.4 824. 82 82 8 88 822 82.6 8 84 82. 82 826. 830 820 82. 822.4 82 8. 8. 82. 860 826. 850 8.2 870 82. 8 8 820 88.6 8 846 840 84. 830 86 8. 84 8 8 82 8 8 8 8 8. 822 82 88 826.8 848 88. 88 8 8. 86 82 88 82.2 84 8 8 8.4 8 8 846 82 8.8 82 82 82 82 82 82 82 82 824 82 830 850 82.8 822 840 84. 8 82 82 8 84. 824 8 820 8.2 84 86. er 82 8.6 82. 39°50’N ARMENIA 84 iv 822 8.2 R 82. 8 di 84 8.6 82 8 Ve 82 8.8 810 8 86. 8. AA 8.8 84 8 82 tudy area tudy area 8 82 850 otentiometric contourhos eleation at hich ater ould hae stood in tightly cased nonuming ells in 26. ontour 8. interal meters. ashed here inferred. atum is orld 8.2 eodetic ystem of 84

stimated direction of groundwater flow 86. TURKEY 8 862 ell for which water leel was measured in 21umer is aterleel eleation of hydraulic head in meters aoe IRAN orld eodetic ystem of 84 tale 4. n areas of high ell density not all aterleel alues are shon

Base from U.S. Geological Survey Shuttle Radar Topography Mission 0 5 10 15 20 KILOMETERS World Geodetic System of 1984 projection, Web Mercator Auxiliary Sphere 0 5 10 15 20 MILES

Figure 14. Potentiometric surface of hydrogeologic unit 6 in the study area of the Ararat Basin in Armenia. Groundwater Conditions 25

43°50’E 44°00’E 44°10’E 44°20’E 44°30’E 44°40’E 44°50'E

844 Kasakh River 86 8. 86. 882 8.6 84 848 88 84 888 860 86. 84.6 84 8 8. 88 8 840 848. 8.8 86 86 88 8.6 8.4 8.4 86. 82 882 8 86 88. 8. 8.8 848.8 850 844. 40°10’N 86.8 82 84 850 8.2 8 86 84 8 88. 826.8 82. 88 8 86 8 84. 8 88. r 82.6 8. 8. 84 82 84 842 844. 8 848 razdan Rive 84 8 84. 830 82. 82.6 H 8 8. 82 866 8.2 844. 8.6 82.8 82 8.8 824 84. 8.6 8 848. 842.4 8 82 84 86 86.2 84 8 82.4 84. 86 84 840 82. 8.8 84. 844 8 82. 842. 844.2 846. 86 8 84. 8 8 846.2 84.6 828 8 82 82. 84.2 8 82.4 84. 84.4 8.2 82 84 82 82 84 82. 84.2 82 8 8 8.2 8. 8. 86.2 84 82 8 8 84 82 84 samor River 842 842 88 8 86 86 84.4 8.86 84 Met 844. 84. 8. 842. 88. 8.2 848 8.8 8 8. 84 842 84 84 8 8 842.2 84.2 84.8 8 8 84. 8 848 84 846 8. 82 8. 8. 8 84.2 84. 84. 844. 846 8. 8 88. 830 84 8.4 82. 86 8 842 8. 8. 848 842.8 84. 842 8. 8 82 84. 8.28 8 844. 84 842 84 842.2 88 86.8 842 88 842.4 84. 84 8 842.8 8 84.8 84. 844 84 84.8 88 86 86 8. 8 84. 84. 84 842 84 8.8 82 86. 84 84 84 84 84 84 8.6 8 844. 8. 82.6 84.2 84. 84. 842 8 88. 82 8. 868 84. 84.4 8 8 8. 8.4 82.8 84. 88. 84. 842 844 84 88.6 82 84.2 84. 8 84.8 84. 8.8 840 84.6 84 8. 86.4 84.8 8 8. 88 84. 8. 86. 8 82. 8 84 86. 8.8 84 8 88. 88. 8.8 84.4 8.6 8. 84. 8 84. 82 8 84. 842. 8. 88 8.2 82. 8. 88 844.6 84 8 8 86 8 8 8 84 8 84.2 84.6 82.6 82. 8.8 82 84 84 8. 84. 8 8 844.2 84 8 84 84 84 84 842 8 82.8 82 86 8. 84.2 86 844 88. 88. 8.4 8 8.8 840 84 8 8 84 88. 8. 8 82. 86. 8.8 8 900 84 8.4 8.2 8 8 8 848 8. 8.2 842. 828. 8.8 82 826 82 88 82. 86 84 82. 8.2 82 86 8.8 88. 8 84. 82 8.2 8. 828.4 8. 850 850 88 8. 842. 84 8. 8. 8. 8 880 8 84.6 84.68 84 8.8 86. 84. 8 8. 8. 82 82. 86. 8 82. 82.6 82.8 8. 4 860 84 8 84. 82. 82.2 86 870 82 846 84 8.4 8 8. 8.2 8. 830 82.64 8 84. 84.8 842 8. 82 82.8 82. 8 8 8 82.2 84 84 84.2 86.8 828. 82. 82. 84.24 844.2 84 8.8 8 82.4 82.6 8 84 84. 82.8 82. 8.6 82 82.4 86.8 86. 8. 82. 8.2 82. 826. 8. 84 84.2 82. 826. 8. 842 842.8 8. 86.6 82.2 82. 82 84. 8.2 Aras River 82. 8 82 er 8. 82.2 v 82.2 82. 82 82 i 828.6 822 R 82. t za 40°00’N 826.2 A 82. 84 82. 88 824 88 82.2 8 840 824 82 824.8 8.6 82 84. 84 8 82 82 8. 82.8 Aras River 8.2 8. 82. 82. 82. 82.4 82 82.2 82.2 824. 84.2 8 82.8 82 82.4 82082. 824.6 8. 88 828 8 842 824.2 826. 86. 82. 82. 822 88 8. 8 822 830 88 82.8 8.4 828 828 820 82 88 828 82 84 8 82 8 810 8.4 8 8 8 88 8 84.8 8 82. 8 84 8 8 88 828 .6 84. 828 82 84 8 88 8 820 88

er iv R 39°50’N ARMENIA di 84. Ve 82 84 AA 810 88 86. tudy area 82 tudy area 82 otentiometric contourhos eleation at hich ater ould 850 86.2 84.2 hae stood in tightly cased nonuming ells in 26. ontour 88. interal meters. ashed here inferred. atum is orld 88. 8 88. eodetic ystem of 84 86.2 8 84. 8. 8. 8. 8 82 stimated direction of groundwater flow 8. TURKEY 8. 86. 8 8 ell for which water leel was measured in 21umer is 8. 8. 8. 8 8.2 82 aterleel eleation of hydraulic head in meters aoe 86.8 8. 8.6 IRAN orld eodetic ystem of 84 tale 4. n areas of high ell 86.2 density not all aterleel alues are shon 8.2 82. 8.

Base from U.S. Geological Survey Shuttle Radar Topography Mission 0 5 10 15 20 KILOMETERS World Geodetic System of 1984 projection, Web Mercator Auxiliary Sphere 0 5 10 15 20 MILES

Figure 15. Potentiometric surface of hydrogeologic unit 8 in the study area of the Ararat Basin in Armenia. 26 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

Hydrogeologic unit 8 is the deepest of the aquifer units different order) were combined (for example, wells with a use and it is confined in the study area. Groundwater-flow direc- of “drinking-household, irrigation” were combined with wells tion is from the south to north (away from the Aras River) in with a use of “irrigation, drinking-household”); and (4) wells the western part of the study area (fig. 15). Groundwater flow with multiple uses but with fewer than 10 wells in the cate- is from west to east and north to south (toward the Aras River) gory were combined into a “multiple use—undifferentiated” elsewhere in the study area. The large spacing between poten- category. Additionally, the 127 wells flowing to waste were tiometric contours in the center of the study area coincides included in water-use percentages as a consumptive use with areas of heavy groundwater withdrawals and high well (fig. 19). densities in hydrogeologic unit 8. The large spacing between By water-use category (fig. 19), the largest percentage of potentiometric contours in hydrogeologic unit 8 in the center the wells (42 percent) was used for irrigation purposes. The of the study area could indicate high transmissivity relative to second largest percentage was aquaculture, primarily as fish areas with closer contour spacing. farming, which constituted 17 percent of the wells, followed by drinking-household (15 percent), drinking-household plus irrigation (15 percent), and unused (flowing to waste) Water Use (7 percent). When possible, well discharge data were collected during Data collected from 2,807 wells in 2016 (table 4) were the 2016 well inventory (table 4). Discharge data included used to summarize the water use in the study area (fig. 16). wells that were not permanently closed, sealed, or temporar- There were 1,012 wells (36 percent) classified as nonopera- ily closed (as indicated by the “Present (2016) status of well” tional, sealed, or temporarily closed. Of the nonoperational column in table 4). For wells with a pump (coded as “yes” in wells, 127 wells were free-flowing and designated as aban- the “Pump (yes or no) or self-flowing” column;table 4), the doned wells. An example of an abandoned flowing well is well discharge values represent the capacity of the pump and shown in figure 17. Abandoned wells create environmental not the actual discharge. hazards (such as pathways for contamination from the land Maps of well discharge rates for flowing wells used for surface to reach the aquifer if well casing deteriorates in irrigation and for fish farming in 2016 are shown in figures nonflowing wells) and continued depletion of the artesian 20 and 21, respectively. The total discharge rates for wells aquifer from flowing wells (Carter and others, 2016). used for irrigation was 2,200 L/s. In contrast, the total well The locations of the abandoned flowing wells are shown discharge rates for fish farming were more than 11 times in figure 18. The sum of the water discharge (as provided higher at 24,900 L/s. This difference could indicate that even through the 2016 well inventory [table 4]) from the 127 aban- though fewer wells were used for fish farming than irrigation, doned wells flowing to waste was 1,090 L/s, which is an the amount of groundwater withdrawals from the confined annual volume of about 34 billion liters. Most of the aban- aquifers likely is much higher for fish farming than irrigation. doned wells flowing to waste (75 percent) had previously been used for fish farming. The maximum discharge was measured at 41 L/s (table 4). Plugging and sealing of the abandoned Changes in Groundwater Levels and Well wells could reduce groundwater depletion and potentially Discharge restore aquifer water-level pressure. Wells discharging the highest volumes (table 4) could be plugged first if resources The increasing number of flowing artesian wells has are limited. The abandoned well flowing 41 L/s identified reduced the aquifer’s head pressure. As a result, many flowing during the 2016 well inventory was plugged and sealed in wells have stopped flowing (Armenian Branch of Mendez 2017 as a first step by the Armenian government in controlling England and Associates, 2014; Carter and others, 2016). Addi- water flowing to waste, and other wells are planned for plug- tionally, the reduced aquifer pressure caused decreased well ging and sealing (Lilith Harutyunyan, ASPIRED program, oral discharge rates. For 23 wells listed in table 6, discharge rates commun., 2017). (well yields) decreased by an average of 94 L/s from 1981 to The water use by well in the study area was grouped into 2013. In the same 23 wells, water levels decreased between several categories. The categories were based on data from about 2 m and 15 m between 1981 and 2013, with a mean the 2016 well inventory (table 4) that classified 1,795 wells water-level decrease of about 9 m. (64 percent) as operational. For simplicity, some categories As shown in figure 10, the pressure boundary (boundary listed in the 2016 inventory were combined. The categories between flowing and nonflowing wells) shrank between 1984 and percent water use in 2016 are shown in figure 19. The and 2016, indicating that a large area has been affected by following categories were grouped from the 2016 inven- groundwater depletion. A spatial analysis was performed using tory list of categories: (1) wells with a use of “land water- GIS software for the pressure boundaries for 1984 and 2016 ing” were classified as “irrigation;” (2) wells with a use that (fig. 10). The area within the study area with flowing wells included “hydrogeological monitoring” were classified by (within the pressure boundary) was approximately 619 km2 their consumptive use or uses; (3) wells that had more than in 1984 but decreased to 291 km2 in 2016. This is more than a one use but had the same combination of uses (just listed in a 50-percent reduction in area between 1984 and 2016. Groundwater Conditions 27

A. Irrigation B. Drinking water Number of wells: 1,467 Number of wells: 632

ARMENIA ARMENIA

TURKEY TURKEY

IRAN IRAN

C. Fish farming D. Industrial and monitoring Number of wells: 533 Number of wells: 81 and 54

ARMENIA ARMENIA

TURKEY TURKEY

EPLANATION Industrial

IRAN Monitoring IRAN

Base from U.S. Geological Survey 0 20 40 KILMETERS orld Geodetic System of 184 proection, eb Mercator Auxiliary Sphere 0 20 40 MILES

Figure 16. Spatial distribution of wells with various water uses in 2016 in the study area of the Ararat Basin in Armenia. 28 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

The shrinking area of flowing conditions has affected than 5 percent had values between 2,000 and 3,000 µS/cm, urban and rural communities. The flowing artesian wells and less than 1 percent of the wells had values greater than supplying drinking water and irrigation water to 31 communi- 3,000 µS/cm. ties have ceased flowing. The Armenian Nuclear Power Plant Water temperature was field-measured for 2,470 wells at Metsamor is no longer able to meet its water requirements (table 4). The maximum water temperature was 24.2 degrees from spring discharges (Yu and others, 2014). The locations Celsius. A visual analysis between water temperature and well of previous and current drinking water wells are shown in depth indicated no relation. The spatial distribution of water figure 22. It is likely that the wells that are no longer used for temperature is shown in figure 26. Most wells with cooler drinking water were abandoned because they ceased flowing. water temperatures are within the 2016 pressure boundary or The water-level data collected in 2007 (table 5) and 2016 in the western part of the basin. Wells with generally warmer (table 4) were used to generate a raster grid of the hydraulic water temperatures are in the eastern part of the basin. The heads in both years using GIS software (using inverse-distance typical temperature of groundwater from the artesian aquifer is weighting based on the nearest 12 neighbors; Esri, 2017); 13 degrees Celsius (Meyer, 2015). these years were selected because of the availability of many The stable isotopes of hydrogen (denoted as δD) and water levels in those years. The 2016 raster grid was then oxygen (as δ18O) of the water molecule can be used to help subtracted from the 2007 raster grid to determine the change differentiate groundwater flow paths and probable recharge in hydraulic head between 2007 and 2016 (fig. 23). The largest sources. Water samples for isotope analysis were collected in decreases (more than 2 m) in hydraulic head between 2007 March 2016 to determine potential sources of recharge to the and 2016 fell outside the 2016 pressure boundary. Within the Ararat Basin artesian aquifers. Five sites were sampled: four pressure boundary, changes in hydraulic head generally were groundwater and one surface water (table 7; fig. 1). Additional minimal or indicated slight increases. It should be noted that sampling at more sites is needed for better evaluation and the areas where increases were indicated are areas with little possible differentiation of recharge sources. overlapping water-level data between 2007 and 2016 (there were many more wells in 2016 than in 2007), which likely affected the accuracy of the analysis.

Water Quality

For the 2016 well inventory (table 4), specific conductance and water temperature were field-measured by Armenian partners using methods described in the “Water-Quality Data” section. Specific conductance measures the ability of water to conduct electrical current (Hem, 1985). Specific conductance can be used to determine the approximate concentration of dissolved solids in water. Water from 540 wells was measured for specific conductance table( 4; fig. 24). The minimum specific conductance value was 377 microsiemens per centimeter (µS/cm), the maximum value was 4,000 µS/cm, and the mean was 998 µS/cm. For 59 percent of the wells, specific conductance ranged from 500 and 1,000 µS/cm. For 32 percent of the wells, values were between 1,000 and 2,000 µS/cm (fig. 25). Less than 4 percent of the wells Figure 17. An abandoned well flowing water to the land surface had specific conductance values less than 500 µS/cm, less in November 2015 in the Ararat Basin in Armenia. Groundwater Conditions 29 20 MILES 4450E Study area EPLANATION 0 to 3 3 to 9 9 to 16 16 to 28 28 to 41 20 KILMETERS [>, greater than] 10 Discharge, in liters per second

4440E e V 0 0 Base from U.S. Geological Survey Shuttle Radar Topography Mission Base from U.S. Geological Survey Shuttle Radar Topography Geodetic System of 184 proection, orld Mercator Auxiliary Sphere eb

Aras River Azat River Azat

4430E

River Hrazdan

4420E

a s

a K 4410E Aras River IRAN 4400E ARMENIA

Metsamor River Study area 4350E ocation of and well discharge from nonoperational, abandoned flowing wells with to waste in 2016 the study area Ararat Basin Armenia. TURKEY L

Figure 18. 4020N 4010N 4000N 350N 340N 330N 30 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

1 percent

7 percent

15 percent EPLANATION Water use category

Drinking—household Drinking—household plus irrigation 15 percent Fish farming 42 percent Industrial Industrial plus drinking—household Irrigation Multiple use—undifferentiated 17 percent Unused—flowing to waste

1 percent 2 percent

Figure 19. Percentage of wells by use of water based on wells inventoried in 2016 in the study area of the Ararat Basin in Armenia.

Fish farm that raises sturgeon, trout, and other cold-water fish using groundwater withdrawals from an artesian aquifer in the Ararat Basin. Groundwater Conditions 31 20 MILES Study area 0 to 6.5 >6.5 to 16 >16 to 32 >32 to 58 >58 to 113 EPLANATION 4450E [>, greater than] 20 KILMETERS Discharge, in liters per second 10

Aras River Azat River Azat

4430E

River Hrazdan

4420E

a s

a K 4410E Aras River IRAN 4400E ARMENIA

Metsamor River Study area 4350E ell discharge rates for flowing wells used irrigation in the study area of Ararat Basin Armenian 2016. TURKEY W

Figure 20. 4020N 4010N 4000N 350N 340N 330N 32 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia 20 MILES Study area EPLANATION 4450E 0.8 to 45 >45 to 90 >90 to 147 >147 to 221 >221 to 372 20 KILMETERS [>, greater than] Discharge, in liters per second 10

Aras River Azat River Azat

4430E

River Hrazdan

4420E

a s

a K 4410E Aras River IRAN 4400E ARMENIA

Metsamor River Study area 4350E ell discharge rates for flowing wells used fish farming in the study area of Ararat Basin Armenia 2016. TURKEY W

Figure 21. 4020N 4010N 4000N 350N 340N 330N Groundwater Conditions 33 20 MILES 4450E EPLANATION 20 KILMETERS Study area 1984 Pressure boundary 2016 Pressure boundary Previous drinking water wells Current drinking water wells 10

Aras River Azat River Azat

4430E

River Hrazdan

4420E

a s

a K 4410E Aras River IRAN 4400E ARMENIA

Metsamor River Study area 4350E ocations of current (2016) and previous wells used for drinking water in the study area Ararat Basin Armenia. TURKEY L

Figure 22. 4020N 4010N 4000N 350N 340N 330N 34 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia 20 MILES 4450E in meters [>, greater than] 20 KILMETERS EPLANATION − 42 to 5 > −5 to −2 > −2 to 2 >2 to 20 >20 to 73 2016 pressure boundary data with 2016 water-level Well data with 2007 water-level Well Difference in hydraulic head, 10

4440E e V

0 0 Base from U.S. Geological Survey Shuttle Radar Topography Mission Base from U.S. Geological Survey Shuttle Radar Topography Geodetic System of 184 proection, orld Mercator Auxiliary Sphere eb

a z A Aras River

e v

4430E

r H

4420E

a s

a K

r e v

4410E

e M Aras River IRAN 4400E ARMENIA Study area 4350E ifference in hydraulic heads between 2007 and 2016 the study area of Ararat Basin Armenia. TURKEY D

Figure 23. 4020N 4010N 4000N 350N 340N 330N Groundwater Conditions 35 20 MILES Study area <500 501 to 1,000 1,001 to 2,000 2,001 to 3,000 >3,000 in microsiemens per centimeter [<, less than; >, greater than] EPLANATION Specific conductance, 4450E 20 KILMETERS 10

Aras River Azat River Azat

4430E i

r H

4420E

a s

a K 4410E Aras River IRAN 4400E ARMENIA

Metsamor River Study area 4350E patial distribution of specific conductance in water from wells the study area Ararat Basin Armenia 2016. TURKEY S

Figure 24. 4020N 4010N 4000N 350N 340N 330N 36 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

350 317

300

250

200 175

150 Number of wells

100

50 26 18 4 0 <500 500–1,000 1,001–2,000 2,001–3,000 >3,000 Specific conductance, in microsiemens per centimeter

Figure 25. Distribution of ranges of specific conductance values in the study area of the Ararat Basin in Armenia in 2016.

Hrazdan River at Yerevan, Armenia, where water samples were collected for analysis of select stable isotopes. Groundwater Conditions 37 20 MILES 4450E EPLANATION Study area 2016 Pressure boundary 20 KILMETERS 9.8 to 13.8 >13.8 to 14.6 >14.6 to 15.6 >15.6 to 16.9 >16.9 to 24.2 [>, greater than] 10 Water temperature, in degrees Celsius Water

4440E River Vedi

0 0 Base from U.S. Geological Survey Shuttle Radar Topography Mission Base from U.S. Geological Survey Shuttle Radar Topography Geodetic System of 184 proection, orld Mercator Auxiliary Sphere eb

a z A

Aras River River

4430E Hrazdan

4420E a s

K 4410E Aras River IRAN 4400E ARMENIA

Metsamor River Study area 4350E patial distribution of water temperature in wells the study area Ararat Basin, Armenia, 2016. TURKEY S

Figure 26. 4020N 4010N 4000N 350N 340N 330N 38 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

The isotope sample results were plotted with the Global Summary Meteoric Water Line in figure 27 (Craig, 1961). The Ararat Basin water samples fell above the Global Meteoric Water Armenia is a landlocked country located in the moun- Line, indicating the sampled waters have origins from a tainous Caucasus region between Asia and Europe. Armenia slightly more humid source than the global average. The shares borders with the countries of Georgia on the north, waters (four groundwater and one surface-water site) had Azerbaijan on the east, Iran on the south, and Turkey and similar stable-isotope values, indicating similar recharge Azerbaijan on the west. Groundwater supplies 96 percent sources for the sampled wells. The Hrazdan River sample of the water used for drinking water purposes and about (fig. 1) was consistent with the groundwater samples, indicat- 40 percent of all water withdrawn in the country is from ing the river could serve as a source of recharge to the Ararat groundwater. Since 2000, aquaculture demands and other uses artesian aquifer. have increased groundwater withdrawals in the Ararat Basin (Ararat Valley) in Armenia. The Ararat Basin is a transboundary basin located in both Armenia and Turkey. The basin is bisected from west to east by the Aras River. Increased 0 groundwater withdrawals in Armenia resulted in decreased springflows, reduced well discharges, lower well water levels, EPLANATION and a reduction of the number of flowing artesian wells in the Hraden River Ararat Basin. Groundwater well In 2016, the U.S. Geological Survey (USGS) and the −40 U.S. Agency for International Development (USAID) began a cooperative study in Armenia to share science and field techniques to increase the country’s capabilities for groundwater δ D ), in parts per thousand study and modeling. This study is in partnership with USAID/ Armenia in the implementation of its Science, Technology, −80 Innovation, and Partnerships effort through the Advanced Science and Partnerships for Integrated Resource Develop- ment (ASPIRED) program and associated partners, including the Government of Armenia, Armenia’s Hydrogeological O + 10 18 Monitoring Center, and the USAID Global Development Lab −120 and its GeoCenter. The purpose of this report is to describe the δD = 8 δ

Ratio of deuterium to hydrogen ( Global Meteoric Water Line hydrogeologic framework and groundwater conditions of the Ararat Basin in Armenia. The study area includes the Ararat −20 −15 −10 −5 0 Basin in Armenia and was expanded slightly from previous studies to include all wells included in the 2016 inventory. Ratio of stable isotopes oxygen-18 and oxygen-16 (δ18O), in parts per thousand The valleys of the Aras River and its tributaries form the intermountain depression known as the Ararat Basin Figure 27. Isotopic composition of water samples from wells and (also known as Ararat Valley). The Ararat Basin is the most Hrazdan River in the study area of the Ararat Basin compared to arid region of Armenia with annual precipitation of about Global Meteoric Water Line (Craig, 1961). 200–250 millimeters. Despite the arid climate, this region contains the country’s largest agricultural and fish farming zone supported by high-quality water from wells completed into an artesian aquifer (unit) that underlies the Ararat Basin. Recharge to the artesian aquifer is through direct infiltration of precipitation and loss of flow in surface streams, especially in upland areas. Groundwater withdrawn from the artesian aquifer in the Ararat Basin of Armenia is used for municipal, irrigation, energy, industrial, and aquaculture uses. Summary 39

The hydrogeologic framework of the Ararat Basin from west to east and north to south (toward the Aras River) contains basin fill and interbedded geologic material consist- except in the western part of the basin where groundwater flow ing of dense clays, gravels, sands, volcanic basalts, and is toward the north or northwest. Unit 6 has this same general andesite deposits. The basin is divided into a northern region pattern of groundwater flow as unit 4. Hydrogeologic unit 8 and southern region by the Aras River. The northern region is the deepest of the water-bearing units and is confined in the of the Ararat Basin, located in Armenia, is the primary focus basin. Groundwater flow generally is from the south to north area to delineate the hydrogeologic framework, in part, due to (away from the Aras River) in the western part of the basin the sparse well information in the southern region located in and from west to east and north to south (toward the Aras Turkey. Using previously published cross sections and well River) elsewhere in the basin. The flow paths indicate that the lithologic logs, lithostratigraphic units were combined into Aras River is a losing stream (discharging to groundwater) in nine hydrogeologic units. Of the nine layers identified in this the western part of the basin; however, it is gaining (ground- study, four were identified as the potential water-bearing units. water is discharging to the river) in the eastern part. These four units consisted of interbedded sands and gravels Data collected from 2,807 wells in 2016 were used to and fractured basalts. summarize water use in the Ararat Basin in Armenia. The In 2016, using training provided by USGS, personnel water discharge from the 127 abandoned wells flowing to from Hydrogeological Monitoring Center (under contract to waste was 1,090 liters per second, which is an annual volume the ASPIRED program) completed an inventory of wells to of about 34 billion liters. Most of the abandoned wells further define and characterize a hydrogeologic framework flowing to waste (75 percent) had previously been used for in and around the Ararat Basin. This inventory focused on fish farming. By water-use category, the largest percentage approximately 2,800 wells completed in and around the Ararat of the wells (42 percent) was used for irrigation purposes. Basin in Armenia. Historical water-level data were acquired Fish farming constituted 17 percent of the wells, followed from ASPIRED researchers for determining groundwater- by drinking-household (15 percent), drinking-household level changes over time. The ASPIRED program provided plus irrigation (15 percent), and unused (flowing to waste) water-level data from 2007 for about 1,600 wells in the Ararat (7 percent). Over time, the flowing wells under artesian pres- Basin in Armenia. Potentiometric surface maps were devel- sure reduced the pressure in the aquifer. As a result, many oped for four hydrogeologic units in the Ararat Basin based wells that were flowing have ceased to flow. The area within on water-level data from the 2016 well inventory. As part of the Ararat Basin in Armenia with flowing wells (within the the well inventory in 2016, personnel from Hydrogeological pressure boundary) was approximately 619 square kilometers Monitoring Center (under contract to the ASPIRED program) in 1984, but decreased to 291 square kilometers in 2016. This measured specific conductance and temperature in well water is more than a 50-percent reduction in area between 1984 and using USGS protocols. 2016. The largest decreases (more than 2 meters) in hydraulic Nine hydrogeologic units were identified as the primary head between 2007 and 2016 were outside the 2016 pressure units in the Ararat Basin, derived from the well inventory boundary. Within the pressure boundary, changes in hydraulic information provided by the ASPIRED researchers. The basin head generally were minimal or indicated slight increases. was divided into three subregions for purposes of describing Specific conductance and water temperature were the lithology, thicknesses, and density of wells that defined the measured by Armenian partners as part of the 2016 inven- units. The subregions were defined using rivers that flowed tory using USGS protocols. Water from 540 wells were north to south. Water-bearing units were identified using litho- measured for specific conductance. The minimum specific logic descriptions for wells drilled in the Ararat Basin. conductance value was 377 microsiemens per centimeter Data obtained during the well inventory were used to (µS/cm), the maximum value was 4,000 µS/cm, and the generate a map showing nonflowing and flowing wells in the mean was 998 µS/cm. The maximum water temperature was Ararat Basin. The nonflowing aquifer conditions were on the 24.2 degrees Celsius. An analysis between water temperature edges of the Ararat Basin where the basin depth shallows. and well depth indicated no relation; however, spatially, most The artesian conditions and the cold water allowed Armenian wells with cooler water temperatures are within the 2016 aquaculture industries to utilize the naturally flowing artesian pressure boundary or in the western part of the basin. Wells conditions to sustain fish farm operations. with generally warmer water temperatures are located in the Potentiometric surface maps were generated for each of eastern part of the basin. Samples were collected from four the four hydrogeologic units classified as water bearing. In groundwater and one surface-water site by USGS in 2016. The hydrogeologic unit 2, the estimated direction of groundwater stable-isotope values were similar for all five sites indicating flow is from the west to north in the western part of the basin similar recharge sources for the sampled wells. The Hrazdan (away from the Aras River) and from north to south (toward River sample was consistent with the groundwater samples, the Aras River) in the eastern part of the basin. In hydrogeo- indicating the river could serve as a source of recharge to the logic unit 4, the direction of groundwater flow is generally Ararat artesian aquifer. 40 Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia

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For additional information visit https://sd.water.usgs.gov

Publishing support provided by the Rolla Publishing Service Center Valder and others—Hydrogeologic Framework and Groundwater Conditions of the Ararat Basin in Armenia—Scientific Investigations Report 2017–5163 ISSN 2328-0328 (online) https://doi.org/10.3133/sir20175163