The Jordan River is a geographically and historically significant waterway in the Middle East, flowing approximately 251 kilometers through a deep rift valley. It originates in the north, meanders south, and ultimately drains into the Dead Sea. The river forms a major part of the border between Jordan, Israel, and the West Bank, making it a shared resource. Given its long course through different climates, the question of whether it is freshwater or salty is complex, and the answer changes depending on the specific part of the river being discussed.
Defining the River’s Natural Composition
The Jordan River is naturally classified as a freshwater system, particularly in its upper reaches. This classification is based on the low concentration of Total Dissolved Solids (TDS), which are the inorganic salts and minerals dissolved in the water. For a river to be considered freshwater, its TDS concentration is typically under 500 parts per million (ppm). The primary sources of the river’s flow are streams and springs fed by high precipitation and snowmelt from Mount Hermon. These tributaries, such as the Dan, Banias, and Hasbani, initially exhibit very low salinity, often measuring around 20 ppm of TDS.
Geographical Segments and Salinity Variation
The river’s composition changes significantly as it moves through its three main ecological zones. The Upper Jordan River, from its sources to the Sea of Galilee (also called Lake Kinneret), maintains its natural, low-salinity freshwater character. The Sea of Galilee itself is a freshwater lake, although it introduces the first major change in the river’s chemistry. The lake is fed not only by the Upper Jordan but also by subterranean saline springs, which cause the water to become slightly brackish. The water quality here ranges from about 240 ppm to 350 ppm of dissolved solids where it exits the lake, which is still considered freshwater.
The Lower Jordan River, which flows from the Sea of Galilee to the Dead Sea, shows the most dramatic variation. As the river progresses south through the arid rift valley, it naturally accumulates minerals and salts from the surrounding geological structures. This effect is compounded by the discharge of additional saline springs that flow into this lower section, transitioning the water from freshwater toward a brackish state. Salinity levels in the Lower Jordan have been observed to increase dramatically, with Total Dissolved Solids historically reaching concentrations as high as 11,100 ppm in the southernmost sections during dry periods.
The Impact of Water Diversion and Reduced Flow
The current state of the Lower Jordan River is a direct consequence of large-scale human intervention, which has severely compromised its water quality. Extensive water diversion projects, primarily for agriculture and municipal use in Israel and Jordan, have drastically reduced the river’s natural flow. Historically, the river’s annual flow was estimated to be around 1.3 to 1.5 billion cubic meters (BCM), but today, the flow has been reduced to only 250 to 300 million cubic meters (MCM) per year. This massive volume reduction prevents the natural dilution of existing salts and pollutants, concentrating them in the remaining water.
The reduced flow volume means that the river’s base flow is now largely composed of agricultural drainage water, treated and untreated sewage effluents, and diverted saline spring flows. For instance, the chloride concentration in the Lower Jordan has been recorded to rise significantly, sometimes reaching 5,400 milligrams per liter (mg Cl/L) in recent decades. The introduction of agricultural runoff further exacerbates the issue by adding nutrients and chemical contaminants. This combination of reduced flow, high evaporation in the hot climate, and the influx of various polluted and saline sources means the Lower Jordan River no longer functions as a healthy freshwater ecosystem. The water quality in this section is now classified as poor-quality brackish water unsuitable for direct consumption.
The Final Destination: The Dead Sea Connection
The Jordan River’s ultimate destination is the Dead Sea, a terminal lake with no outlet to the ocean. This geographical feature is the reason for the Dead Sea’s notorious hypersalinity. Water delivered by the Jordan River contains dissolved salts and minerals, which are left behind as the water evaporates rapidly in the arid climate. The massive reduction in the Jordan River’s flow is the primary cause of the Dead Sea’s current decline. With its main source of replenishment significantly diminished, the Dead Sea’s water level is shrinking at a rate of more than one meter per year.