Kumisi Lake

Kumisi Lake (კუმისის ტბა) is a relatively shallow lake located in the Kvemo Kartli region of Georgia, situated south of Tbilisi, typically associated with the Gardabani or Tetritskaro municipalities near the village of Kumisi. Unlike many mountain lakes, Kumisi sits in the low-lying Kvemo Kartli plain at an elevation of around 470 meters (approx. 1542 feet). The lake has a unique history, having reportedly dried out significantly, or even completely, in the past before being artificially refilled, primarily for irrigation and recreational purposes.

Historically known for its therapeutic mud (peloids), rich in minerals like hydrogen sulfide and used for balneological treatments, Kumisi Lake’s water was previously described as saline or brackish. However, since being refilled via canals, notably one diverting water from the Algeti River, its water is now primarily freshwater, though likely still mineralized. The lake bed itself consists of clay deposits that form the basis of this curative mud.

Covering an area that has fluctuated but is cited around 5 square kilometers, the lake remains very shallow, with maximum depths likely only a few meters even after refilling efforts (historical depths were often less than a meter). This shallowness contributes to warm water temperatures in summer and likely a nutrient-rich (eutrophic) ecosystem. Kumisi Lake is currently a very popular destination for recreational fishing, often managed as pay-lakes stocked with various carp species, grass carp, crucian carp, and potentially others. It also attracts locals for picnics and relaxation along its shores. Given the current date (April 26, 2025), Kumisi Lake is fully accessible, ice-free, and likely experiencing rising water levels due to spring inflows via the canal system.

Identification and Location:

• Name: Kumisi Lake (კუმისის ტბა).
• Location:
  • Country: Georgia
  • Region: Kvemo Kartli
  • Municipality: Gardabani / Tetritskaro (located near the boundary). Near villages Kumisi, Tsintskaro. South of Tbilisi.
  • Nearest Major Landmark: South of Tbilisi, located on the Kvemo Kartli plain.
  • Coordinates: Approximately 41.61∘ N latitude, 44.70∘ E longitude (approximate).
• Relationship to other bodies of water: Fed significantly by an artificial canal from the Algeti River. Also receives water from precipitation, groundwater, and potentially small local inflows. Has controlled outflow, likely part of the irrigation network.

Physical Characteristics:

• Surface Area: Variable historically; often cited around ≈5−6 km2, though current area may differ based on water management.
• Maximum Depth: Shallow; specific current data needed, but historically very shallow (<1m). Likely a few meters maximum after refilling (reported up to 4m).
• Average Depth: Data unavailable; extremely shallow historically (reported around 2m more recently).
• Volume: Data unavailable; relatively small due to shallowness, highly variable with water level (reported around 11-14 million m³).
• Elevation: $\approx 470\text{ m}$ – 475 m (approx. 1542 – 1558 ft) above sea level.
• Shoreline Length: Data unavailable; depends on area/shape, relatively flat terrain.
• Water Source(s): Significantly influenced by the Algeti-Kumisi irrigation canal diverting water from the Algeti River. Also precipitation, groundwater, minor local inflows. Some reports mention supply via canals from the Mtkvari river as well.
• Outlet(s): Likely controlled outflow via canal system for irrigation.
• Water Type: Historically saline/brackish, now largely Freshwater due to Algeti River input, though likely mineralized. Famous for therapeutic mud.
• Basin Geology: Tectonic depression on the Kvemo Kartli plain. Lakebed consists of mineral-rich clay deposits forming therapeutic mud (peloids), potentially of pseudo-volcanic origin.

Ecological Information:

• Flora (Plant Life): Shoreline likely includes salt-tolerant species remnants mixed with typical lowland grasses, reeds (Phragmites), and rushes adapted to fluctuating water levels. Aquatic vegetation common in shallow areas.
• Fauna (Animal Life): Popular fishing site supports freshwater fish like Common Carp, Grass Carp, Crucian Carp, Catfish, Mirror Carp, Barbel (often stocked for angling). Historically important for water birds; remains a significant site for wintering and migratory birds. Surrounding agricultural land and steppe host associated local fauna.
• Trophic Level: Likely Eutrophic, due to shallowness, nutrient inputs (historical and potentially current via canal/agriculture), and warm temperatures.
• Water Clarity: Likely low to moderate, affected by shallow depth, sediment resuspension, and algal/plankton growth common in eutrophic lakes.
• Water Temperature: Follows seasonal air temperatures; warms considerably in summer making it potentially suitable for swimming. Unlikely to freeze deeply or for long periods. Currently (late April), water is cool.
• pH Levels: Data unavailable; likely neutral to slightly alkaline.
• Dissolved Oxygen Levels: Data unavailable; likely fluctuates, potentially low in bottom layers during summer.
• Unique Ecological Features: Presence of therapeutic (balneological) mud rich in sulfides and other minerals. An ecosystem heavily influenced and managed by human intervention (artificial water supply). Important stopover/wintering site for birds.
• Conservation Status: No major formal protected status (like National Park), but recognized as an important wetland, especially for birds. Subject to water management regulations. Potential candidate for protected area status due to biodiversity and unique mud resource.
• Invasive Species: Data unavailable; introduction of non-native fish for angling is common practice in such managed fisheries.

Human Interaction and Significance:

• Historical Significance: Long known for its therapeutic mud used in traditional treatments and balneology (used at Tbilisi Balneological Resort). Has a documented history of completely or partially drying out and subsequent artificial refilling projects (primarily linked to Soviet-era irrigation schemes, starting around 1960s).
• Current Uses: Major use is recreational fishing (often commercially managed). Source of therapeutic mud. Water is used for local irrigation. General recreation (picnics, relaxing by the shore). Important site for birdwatching.
• Environmental Issues: History of severe water level fluctuations and drying, impacting biodiversity. Water quality potentially affected by inputs via the canal and agricultural runoff. Risk of eutrophication. Sustainability of fishing pressure. Management and potential environmental impact of mud extraction. Waste management from recreational visitors.
• Management and Conservation Efforts: Water levels are actively managed via the Algeti-Kumisi canal system (Georgian Amelioration). Fishing activities are often managed by private leaseholders or associations. Regulations may exist concerning mud extraction. Recent efforts made to improve water supply to prevent drying.
• Local Communities: Provides significant recreational resource (fishing) and potential economic activity related to fishing and possibly therapeutic mud. Supplies irrigation water. Its fluctuating state impacts local perception and use.

Interesting or Unique Facts:

• Famous for its curative mud, used for treating joint, skin, and other ailments.
• The lake has dried out completely (or nearly so) in the past and was subsequently refilled using water diverted from the Algeti River via a canal.
• Its water character changed significantly from saline/brackish to predominantly freshwater due to this intervention.
• It’s a very popular and accessible fishing destination near Tbilisi.
• An important location for birdwatching, especially during migration seasons.
• Located in a region (Kvemo Kartli) known for its rich archaeological history, although the lake itself isn’t a primary historical site.