Rudrasagar Lake
Rudrasagar Lake, also known as Twijilikma, is a lake located in Melaghar, Tripura, India. The Government of India's Ministry of Environment and Forest has identified Rudrasagar as one of the wetlands of National Importance for conservation and sustainable use based on its bio-diversity and socio economic importance. The secretary general of the Ramsar Convention has declared Rudrasagar Lake as a wetland of international importance. This certificate has been communicated by Ministry of Environment and Forests, Govt. of India on 29 February 2007. Geography. The Rudrasagar Lake is located in the Melaghar block of Sonamura sub-division  of Sipahijala district. The lake forms a geographical area of 2.4 km and situated at a distance of about 52 km from the state capital of Tripura. The lake is situated in between 23°29’ N and 90°01’ E. Hydromorphologically, Rudrasagar Lake is a natural sedimentation reservoir, which receives flow from three perennial streams namely, Noacherra, Durlavnaraya cherra and Kemtali cherra. After settling the sediment from the received flow, clear water discharges into the river Gumati through a connective channel namely Kachigang. The lake bed has been formed by silt deposition. As such no rock formation is  found with 50 m is silt (clay loam) and below formation is sandy. Surrounding hillocks are of soft sedimentary formation. Annual rainfall is of the order of 2500 mm. Spread over the months of June to September with four or five flood peaks. Substantial base flow in streams rounds the year. The soil in lake area is silty clay loam to clay loam. Lake water is fresh with insignificant pollution with a depth varies from 2 to 9 m. Fluctuation in water level varies from 9 to 16 m. The downstream area of the lake is 750 ha with a  temperature variation from 37 °C to 50 °C and rainfall during 15 May to 15 October. Rudrasagar is a potential Important Bird Area and attracts a large number of waterfowl in winter. Among the rarer species recorded are the endangered Baer's pochard and near-threatened ferruginous duck. Pollution. The lake has faced the problem of pollution due to the following reasons. Major soil erosion in catchment area of the lake is one of the major problems to decrease the lake area and to decrease the depth of the lake also. Such degradation in catchment area and siltation  in the lake has the effect since long time in the lake. For such reason and others, the area of Rudrasagar Lake has been decreased drastically from 1000 ha. Prior to 1950 to more or less 100 ha. at present. Silting of lakes on account of increased erosion as a result of expansion of urban and agricultural areas, deforestation, flood, immersion of idols by the religious activity and such other land disturbances taking place in the drainage basin of the lake. Neermahal. A palace known as Neermahal (Water Palace) is situated near the north-east bank of the lake. It  constructed by the then Tripura King Maharaja Bir Bikram Kishore Manikya Bahadur in between 1935 and 1938 as summer resort.