Rain water harvesting in Coastal Sand Dunes of Poompuhar by SEVAI

Rain water harvesting sand dunes in coastal Poompuhar by SEVAI-Lost in tsunami

At the most basic level, dunes are simply piles of sand. Sand dunes are present on shorelines where fine sediment is transported landward by a combination of wind and waves, and stabilized with vegetation such as Native Dune Grass. Dunes undoubtedly are one of the most well-known features of sandy beaches, yet they are also misunderstood and abused. Dunes can help protect coastal property from the destructive forces of storm surges and tsunamis, but human activities have had severe impacts on coastal sand dunes. Coastal sand dunes serve a more important purpose than beauty. Dunes act as flexible barriers to ocean storm surges and waves, protect low-lying backshore areas, and help preserve the integrity of low barrier islands. With proper planning and management, their functions may be enhanced. Dune sand is relatively low in plant nutrients, and dune plants are adapted to this condition. However, small amounts of nutrients, primarily nitrogen and phosphorus, supplied by commercial fertilizers, are useful for promoting rapid establishment of trans- plants and encouraging existing vegetation. Fertilizer may also be needed for periodic maintenance. Other plant nutrients are normally supplied from the soil or salt spray.Sand dunes are found at Poompuhar and Keelamoovarkarai coastal areas of Nagapatinam District.  This sand dune system is quite small, less than 2.5 hectares, and has been substantially impacted by human use. However, these dunes do still provide plant and are worthy of protecting and restoring. Dunes are formed when wind and waves transport sand onto the beach. The ultimate source of the sand is often glacial till those resides offshore, or is eroded from nearby cliffs by waves, and transported along the shoreline by long shore currents.Waves wash this sand up on the beach, and also remove it during storms. The shape and size of dunes formed depends on the shape of the beach. In Poompuhar and Melamoovarkarai Thennampattinam coastal belt of Nagapatinam District SEVAI has constructed water harvesting tanks in the sand dune areas and it collected rain water and the water was used for domestic purposes. In 2004 tsunami, the Poompuhar tank was devastated and the sand dunes were bulldozed.-Govin