DSS applications for Water Resources Management in Kerala state 17 Jan 2015 Water Informatics Session India Water Week New Delhi

Model of Bharathapuzha River Basin in DSS Software Hydrological parameters (including groundwater parameters in accordance with the latest GEC) in the basin was fine tuned using NAM & Mike Basin

Benefits from DSS More than 20 applications were developed using DSS tools, which assisted the Higher authorities to make informed decisions in the water resources sector Improvements in the quality of hydrological data. The DSS tools were used to validate the discharge and reservoir data and errors in data acquisition procedures were identified. Trainings on DSS at the state was attended by Hydrology Engineers and presently around 25 engineers can handle the DSS tools The Server installed under DSS can be accessed by the users of the data and has enabled the integration of Ground water and Surface water data. Government had decided to apply DSS to all River basins of Kerala for improved water resources planning.

New technological practices in water resources sector adopted by the team for the development of applications during the DSS periods The Rainfall-Runoff modeling tool NAM was used to obtain runoff of un- gauged stations, to ascertain water availability at select locations in river, to extend the available time series etc. MIKE Basin was used to model the allocation of available water to different users, to model reservoir operation, to determine the optimum reservoir capacity by varying the dam height etc. The Digital Elevation Models were used to trace the river, to delineate catchments for selected river locations, to prepare contour lines, to find depression in terrain for developing into a reservoir, to find reservoir volume, to find area of submergence etc. Proficiency in GIS software. The major & minor rivers of Kerala were digitized during HP I. Preparation of 3D maps. The use of GPS was improved by loading custom made shape-files to transfer locations of proposed dams and inundation area to ground at site.

Application I - Kuriarkuty Karapara Irrigation Project THE PROJECT The aim of the project was to provide water to the rain shadow regions of Kanjikode & Kozhinjapara area in Palakkad district HISTORY The project was conceived 3 decades ago but did not materialize due to submergence of forest area & Uneconomical hydroelectric power potential The project was analysed using the DSS tools and an alternative proposal was made without forest submergence and also an increased peak hour power

As per the DSS proposal, locations and height of the dams were changed Reservoir was shifted to non forest area. Approx. Cost of the project would be 1500 Crores Benefits Water availability at rain shadow region increases by 90Mm3 during summer. Peak hour production of power of 200 MW. Only diversions dams and No forest submergence Savings of huge preliminary investigation cost and man hours The Government is convinced about the new proposal and as per order No. IDRB/ISW/AD1/433/2012 dated 15.12.14 a technical committee has been constituted to conduct further detailed investigation for the preparation of DPR

Application II - Artificial Recharge Viability Analysis Total ground water recharge from all the structures – 1.919 MCM/Year A project proposal amounting to 7.5 crores was submitted to the Government and the scheme is expected to be included in the State Budget for the year 2015-16

Application III - Managing Drinking water supply to Trivandrum city The monsoon of 2012 was very weak and the reservoir level of Peppara dam which supplies drinking water to Trivandrum city was alarmingly low by the end of south west monsoon period in September 2012. The problem was analysed with DSS tools and DSS team was able to provide suggestions on optimal reservoir operation like curtailing the power production, which was implemented and uninterrupted drinking water supply was ensured. Moreover the viability of construction of 3 check dams proposed at a cost of 15 crores was analysed using DSS tools and was found to be ineffective and hence dropped.

Application IV - Alternate source for drinking water to Kollam City The drinking water supply of Kollam city is from Sasthankotta fresh water lake, which has only 12 km2 of catchment area. During the drought of 2012-13, the lake started drying up and reached the lowest recorded level. An alternate source (Kotakayal lake with catchment area of 160 Km2) was proposed by the DSS team. On analysis it was found that this saline lake could be converted to fresh water lake by constructing a 50 m bund at the exit in down stream direction thereby preventing the saline water intrusion. The fresh water availability on construction of bund was analysed with DSS tools and yielded fruitful results.

Application IV - Augmenting drinking water supply to Trivandrum The drought of 2012-13 called for the revival of Vamanapuram Irrigation Project, which was once abandoned because it could cause forest submergence and also there was opposition from the local people. The revival of the project will improve the drinking water availability of Trivandrum city and irrigation requirement of Vamanapuram Basin. DSS team made an alternate proposal of construction of two small dams to divert water from Vamanapuram basin with minor reservoir to existing Peppara reservoir. The proposal was analysed using DSS tools and the integrated operation of 3 reservoirs were modeled in DSS software and was found feasible.

Application V - Analysis of river linking The Meenachil River dries up during the dry weather causing water scarcity in the Kottayam city and other towns on its bank. The adjacent Muvattupuzha River is having steady flow through out the year, being in the downstream of large hydroelectric scheme at Idukki. The possibility of diverting some of the tail water from Muvattupuzha to Meenachil was analysed in Mike Basin.

Other Important DSS applications 1. Conjunctive Use The acute water shortage at the tail end of Chittur irrigation project ayacut area was analysed and a plan for conjunctive use of ground water and canal water was proposed . 2. Check dam locations in Bharathapuzha, Chalakkudy, Meenachil and Pambar Basins The check dam locations were identified in the 4rd and 5th order streams and in the main rivers to improve the ground water recharge and to improve the dry weather flow in the main river. The locations were identified using ASTER DEM and Google earth. Field verification was done by the field officers for ascertaining the suitability of sites. The recharge values were calculated from DSS software. 3. Water Quality module The pilot basin Bharathapuzha, does not pose much water quality issues, but the application was developed to explore the capabilities of DSS Water quality tool in other River basins. The BOD parameters were taken up for studies and the data of WQ stations of CWC were used.

Water yield of the basin Integrated Reservoir Data 4. Irrigation module An attempt application on Irrigation module was carried out for Chittur area in Bharathapuzha basin. The application was successfully run for a canal network. 5. Water yield of the basin The water availability of the Bharthapuzha basin was computed as part of the preparation of Water Atlas for the state. Simulated discharge of the sub basins for the last 30 years had been obtained from the available rainfall data and was tabulated. The water availability for various Lift irrigation schemes were also analyzed. 6. Integrated Reservoir Data Simulated data of seven reservoirs in the Basin was integrated using DSS (P) Software spread sheet module. Inflow, Water level, Demands etc. can be viewed and exported to MS Excel. This will help Officers involved in Reservoir planning to take decisions on Water allocation.

Study on transfer from Silent Valley to Malampuzha reservoir 7. Study on transfer from Silent Valley to Malampuzha reservoir Feasibility of water transfer from abandoned silent valley project was taken up using DSS tools. 8. Flood mitigation studies- Kuttanad Flooding studies were conducted using DSS tools in Kuttanad wetland area where 5 major rivers empty to Vembanad lake. Alternate diversion channel to sea without entering the area were identified and reported. 9. Flood mitigation studies- Thampanoor, Trivandrum Thampanoor at the heart of the Trivandrum city experiences frequent flooding. The problem was analyzed with DSS tools to ascertain the quantity of flood water and time of concentration to propose diversionary Channel. 10. Viability analysis of Dams at Murinjapuzha, Pattissery… Proposal of a storage dam in Manimala river by a local expert was reported in the newspapers. The area was surveyed with Digital Elevation Models and operation of reservoir was modeled in DSS. The terrain is steep in nature and hence the reservoir storage for even high dam is low. The proposal was dropped after the DSS analysis.

11. 12. 13. 14. Hydro-electric potential of Pazhukkakanam dam site A hilltop with 4.5km2 catchment area in Meenachil Basin was having a waterfall of 200m in the rainy season. There was a proposal to install a mini hydropower station for taping the power potential. Hydropower module of the DSS software was used to model the Power availability. The proposal was uneconomical as per DSS analysis and hence dropped. 12. Leachate intrusion study of Vilappilsala solid waste disposal site The solid waste disposal site of the Trivandrum city was polluting the nearby Karamana river and the City Corporation wanted solution to mitigate it. The area was studied for ascertaining the ground water & surface water flow and remedial measures were suggested 13. Data rectification using DSS tools The rainfall runoff model - NAM was used to model catchment areas of the gauging stations to verify the observed discharge. The simulated discharge from NAM using measured rainfall was used to validate the data collected by the field stations. Some discrepancies were identified in the collected data and the data acquisition procedures were changed. 14. Developing IWRM for Basin The Integrated Water Resources Management were introduced in the Basin report prepared by the Hydrology wing. The role of various stake holders of the basin was redefined and a comprehensive study of Shiriya basin was undertaken.

Thank You