the Atlantic Ocean. One significant exception is the Ebro, which flows eastward to the Mediterranean. Rivers in the extreme northwest and in the narrow northern coastal plain drain directly into the Atlantic Ocean. The northwestern coastline is also truncated by rias, waterbodies similar to fjords. The major rivers flowing westward throughout the Meseta Central include the Duero, the Tagus, the Guadiana, and the Guadalquivir. The Rio Guadalquivir is one of the most significant rivers in Spain because it irrigates a fertile valley, thus creating a rich agricultural area, and because it is navigable inland, making Seville the only inland river port for ocean-going traffic in Spain. The major river in the northwest region is the Miño. El Atazar Dam is a major dam built near Madrid to provide a water supply. Floods and erosion Certain Spanish regions can be considered vulnerable to both flooding and erosion. 15 October 1879, in Murcia, Santa Teresa flood. 13–15 October 1957, in Valencia, torrential rain results in a devastating flood, at least 81 people lost their lives. In 1982, the river Jucar (Valencia, Spain) broke the Tous Reservoir causing a flood that killed 30 people. Water stress Water stress or water lack, poses the greatest threat in Spain. Water scarcity is a significant issue in many regions throughout Spain and climate change may aggravate the problem, with longer periods of dry weather. Supply problems regularly occur in the Jucar basin during summer. In the Segura basin, water scarcity has resulted in an increase of the water prices by 30% for households. Overall, the regions in the south-east of Spain are particularly vulnerable to water shortages. Furthermore, large areas of the Mediterranean are affected by saltwater intrusion. Climate Peninsular Spain experiences three principal climatic types: semi-arid, maritime, and Mediterranean. The locally generated semi-arid climate covers the majority of peninsular Spain, influencing the Meseta Central, the adjoining mountains to the east and the south, and the Ebro Basin. This climate is characterized by wide diurnal and seasonal variations in temperature and by low, irregular rainfall with high rates of evaporation that leave the land arid. Annual rainfall generally is ; most of the Meseta region receives about . The northern Meseta, the Sistema Central, and the Ebro Basin have two rainy seasons, one in spring (April–June) and the other in autumn (October–November), with late spring being the wettest time of the year. In the southern Meseta,