Burma Nagar Pond
Burma Nagar Pond has been chosen for restoration by CMWSSB as part of the Sustainable Water Mission. The pond is located at the end of 13th Street, Burma Nagar in Tiruvottiyur. The pond is surrounded by revetment along with steps. Both the revetment and steps that were damaged in the 2015 floods have been renovated. Profuse growth of prosopis along the bund was removed. Inlet and outlet provisions were made in the pond. The pond is free from encroachment and is not polluted with solid waste dumping. Diverting sullage or sewage into the pond is prevented and blocked. The open area located to the north of the pond is the major catchment to the pond. The eastern side of the pond along the playground is provided with barbed wire fencing. The pond has been restored under the Chennai Smart City project funds.
Area, Zone, Division
AREA :2428.116 Sq.mtrs. , ZONE : 2, Division : 16
This pond is in Division 16 of Zone – 2 and is located at the end of 13th Street, Burma Nagar. It is located to the North of the road. The pond is located at North Latitude 13°11'4.50" and East Longitude 80°16'56.60".
Field Observation and Inferences
The pond is rectangular in shape. There is water in the pond during the time of survey. The pond is provided with revetment all around and also with steps. Both the revetment and steps have to be reworked as it got damaged in the 2015 floods. The bund is with profuse growth of prosophis. Inlet and outlet provisions were made in the pond. The pond is free from encroachment and is not polluted with solid waste dumping; Neither sullage nor sewage is diverted into the pond. The open area located to the north of the pond is the major catchment to the pond. The eastern side of the pond along the play ground is provided with barbed wire fencing. An HT line cross over the pond. Far west of the site is a container terminal located. Based on the interaction with the local community, it is inferred that the pond use to hold water for about 9-10 months in a year and the pond water is used for bathing and washing purpose.
Shallow openwells are the common groundwater extraction structure in this area. Proximity of the site to the Ennore creek makes the ground water saline in the area. The Total Dissolved Solids of the openwell water is tested and found to be more than 6000 mg/lt. The depth to water level at the time of study is at 2m below ground level. One of the major advantage of this pond is that it is not polluted neither by solid waste dumping nor domestic liquid waste diversion. There is no weed infestation found in the water spread area.
The pond can be renovated with minimal interventions. The thorny bushed along the bund to be removed. The inlet and outlet channels should be strengthened. The revetment and steps should be re worked. The pond can be provided with a barbed wire fencing and provided with a wicked gate. The run off from the open areas and from the play ground can be channelized into the pond. This requires cautious approach as there is waste water generated in the colony area gets stagnated around the pond which should not get diverted in to the pond.
Based on the TSS output, it is inferred that the total area of the pond is 2478.42 sq.m and the total length of the bund is 198.95m. The average depth of the pond is about 1.5m.
Impact of Urbanisation
The imagery extracted from google earth on 16.04.2017 and 17.06.2013 is presented below shows no major change on the water spread area of the pond but for the partial removal of tress on the bund.
Google Image of the pond as on 16.04.2017 (LEFT) and 17.06.2013 (RIGHT)
Pond Storage Estimation
The actual volume stored in the tank during 1987 –a normal rainfall year - after losses due to evaporation and recharge is given in the following Graph
The total storage of the tank in its present condition is estimated at 3717.63 cu.m. Based on this estimate, there will be water available in the pond for almost 135 days in a year. At no point of time, the pond overflows in a normal rainfall year. The total inflow to the tank in a normal rainfall year is estimated at 4531.95 cu.m; the total groundwater recharge will be 2998.89 cu.m.
The estimate was made in an excess rainfall year ie., during 2005 to see the inflow and outflow status. The actual volume stored in the tank after losses due to evaporation and recharge is given in the following graph.
Based on this estimate, there will be water available in the pond for 268 days. The pond in its present volume does not over flows even in an excess rainfall period for the assumed catchment. The total inflow to the tank in an excess normal rainfall year is estimated at 6048.50 cu.m; the total groundwater recharge is 2080.3 cu.m.
Based on the field observations and inferences, followed by the data analysis, following were the list of activities proposed for renovating the pond.
The pond should be dewatered, desilted and deepened.
The bund need to be trimmed, strengthened;
Revetment and steps to be reworked.
Bush clearance all around the pond and provision of a pathway all around the pond to a width of 2m and properly fenced.
Surface run off from the open grounds can be channellised to the pond without diverting the waste water through a filter chamber.