Taming the rivers (The Tribune 08 October 2010)

If flood storage is made a part of all dam projects, miseries caused by floods and drought can be minimised. The strategy, therefore, should involve integrated planning and management of land and water resources
THE wet season this year has led to a rude awakening, particularly in J&K, Himachal, Punjab, Haryana and Delhi. The importance and complexity of water-related problems attributed to several causes is being voiced by a cross-section of society. While normal life in the hills was paralysed by landslides and soil erosion, the plains got inundated for weeks, causing a massive loss of lives, crops and property. On other side, states like Bihar, eastern UP, Jharkhand and parts of West Bengal faced a drought syndrome. In both cases, normal life and socio-economic conditions were affected by a revealing contrast of an excess of and deficiency of the monsoon.
Victims of a flood fury near Patiala. Tribune photo: Rajesh Sachar
We cannot alter the weather pattern or influence an occasional El-Niño phase controlling it over a period varying from three to seven years. However, distress resulting from such events can be minimised to a great extent by integrated management of the land and river system comprising the catchments, drainage lines, feeding streams, floodplain and the main river channels.
For many years decision-making over land use has paid limited attention to hazards associated with the water environment. Short-term and piecemeal commercial interests are often pushed through in a compartmentalised mode ignoring the fact that the river, its catchments, floodplain and groundwater are essentially a hydrological, geomorphologic and ecological continuum. A holistic approach generally emphasised is not compulsorily translated into a master plan format for sustainable development of the resource.
Guidelines for the preparation of a river basin master plan with a 25-year perspective were prepared by the Central Water Commission in 1990. These can be modified and used as per the local terrain, climatic conditions, basin specific features, including the frequency of floods and drought. A periodic review of the plans is necessary to update and improve them incorporating changes on account of new developments in the intervening period.
While some states and central agencies have already taken the initiative, most others are still pursuing a project-to-project approach with overlapping features and conflicting interests. The World Bank and the Asian Development Bank are funding projects for the preparation of the master plan for the basin's water resource to promote its integrated development. The states can take benefit of such institutional funding.
Every state should have a master plan for each of the river system within its territory. For inter-state rivers, the master plan prepared by a state for river reach within its jurisdiction may be amalgamated and approved by the central government.
The problem of floods and drainage congestion faced by Delhi is not new. A master plan for drainage was prepared way back in 1976. Its implementation could not keep pace with fast urbanisation. Later, a technical committee was constituted by the Lt Governor of Delhi in 1993 (this writer was its member from the CWC) to find out inherent defects in the existing drainage system and suggest measures for improvement. The committee studied all aspects in detail, undertook field visits, interacted with various functionaries and public representatives in Najafgarh, Barapulla, Shahdara, Bawana and also drainage basins in the neighboring Haryana territory falling into the Yamuna river from its right bank.
Apart from coordination with multiple construction agencies for rigorous enforcement of the drainage standards as well as its pre-approved layout plan, the other important issues requiring the attention of the Delhi government are: pre-monsoon cleaning of drains and removal of obstructions, floodplain zoning and regulation, flood-risk mapping, flood insurance and improving embankments to contain backwater effect of three barrages viz Okhla, ITO and Wazirabad when the Yamuna is in spate. The old master plan for each major drain should be updated every alternate year for incorporating changes in the landscape. The area-wise action plan evolved earlier may also be updated and implemented keeping pace with rapid urbanization.
In case of Haryana, the major river Yamuna flowing along its eastern boundary has two barrages at Dakpathar and Asan in Uttrakand territory upstream. The third barrage at Hathnikund is located in Haryana. None of them has flood storage. Maneuvering of the excess influx due to heavy rain in the upper basin is not possible. Embankments along the river have provided some defence from floods but once breached, inundation of the adjoining areas in Yamunanagar, Karnal, Panipat, Sonepat, Faridabad etc is imminent.
The other small rivers in Haryana -- Tangri, Markanda, Ghaggar and its tributaries originating in the fragile shivalik hills, Som and Pathrala -- have sufficient damage potential during the monsoon. NH-1 is often submerged and damaged affecting mobility in the entire region. These rivers are seasonal and carry quasi totality of sediment in a flash flood. It is important to prepare a separate master plan for each of them. Water and sediment yield of these small basins may be assessed for constructing cascade of small dams to intercept sediment and store run-off. The emptying of dams and flushing of sediment before the onset of the monsoon starting from the most upstream are necessary. The filling of the empty dams should start from the most downstream one. When properly constructed, maintained and operated, these measures can moderate floods, enhance water availability in the lean season, recharge aquifers and improve the ecology of the degraded Shivalik ranges.
Three major rivers -- Beas, Ravi and Satluj -- meander through Punjab in their lower stretches. Most of the annual flows to these rivers is contributed from Himachal territory upstream. The monsoon run-off in Punjab area is evacuated by seasonal streams like the Ghaggar, White Bein, Black Bein, Sakkikiran and numerous "choes" carrying debris in flash flood . Ranjit Sagar on the Ravi river is the only dam in Punjab. It is primarily a hydropower project having irrigation as an additional component. All the main rivers in Punjab territory are mostly embanked supported by spurs. When breached, large areas in the Amritsar, Gurdaspur, Jalandhar, Ferozepur, Phagwara, Nawanshahar and Ropar areas are affected by floods.
Jammu and Kashmir does not have a serious problem of floods except that the Tawi river occasionally inundates low-lying areas before exiting to join the Chenab in Pakistan territory. Flash floods in seasonal streams and landslides are but matters of concern. The Leh region was severely jolted by a catastrophe during the early part of August. Several inhabitations were wiped out and hundreds of lives lost. The state has three hydroelectric projects at Baglihar, Dulhasti and Salal on the Chenab river. Uri-I and Uri-II hydropower projects are on the Jhelum river. Though on the main rivers, none of them has a flood cushion to hold the monsoon run-off.
Before entering the neighboring states, the major rivers originating in Himachal or flowing through it have the Bhakra reservoir on the Satluj river. The Nathpa-Jhakri project on the same river is a run of the river type for power generation and has to be shut down for weeks during the monsoon due to an excess sediment load. In between the Kol dam in the offing is also for hydropower. The Beas river has the Pong dam for irrigation and power generation. The Pandoh dam in the upstream is for the diversion of the Beas water to the Satluj river for supplementing Bhakra irrigation and power generation. The other projects in the Beas basin like Larji, Parbati-I, II, III and Malana are for hydropower generation. In the Ravi basin, the power projects are Baira-Siul and Chamera. All of them are in HP territory.
Each off these major river basins has three or even more dam projects but none with dedicated flood storage. The leverage of extra flood cushion would have given the much-needed flexibility to hold excess water and regulate its release for attenuating the high flow. This at a small cost of the entire project could have also taken care of the peak load of power and irrigation demand in a lean season. In its absence, the inundated areas downstream may have to learn to live with similar floods unless the future projects are designed for flood moderation and their integrated management resorted to by the co-basin states. At present only the empty space out of the designed storage in the Bhakra, Pong and Ranjit Sagar dams can absorb some of the monsoon inflows to provide incidental flood relief, which as already seen, is not enough to mitigate the real problem.
Some sense of flood security is provided by embankments along the rivers in the plain reach and the location specific dykes in the urbanised areas. These structures are generally at risk from floodwaters flowing under, through and over them undermining their stability. It is difficult to protect or reconstruct them during floods Therefore, vulnerability of the structures should be assessed well before monsoon and strengthening measures taken with proactive planning.
River form is the end product of complex fluvial processes and keeps on changing in response to water flows or sediment inputs. It is a proven fact that any kind of obstruction in the natural river domain could lead to serious consequences. There being no mechanism to regulate the floodplains in the country, several industries, habitations and institutions have come up on the river right-of-way and cannot escape the fury of floods.
The antidote to distressful floods and drought has to be pursued with more powerful multi-disciplinary means. Plantation in denuded catchments can be a part of it but not enough by itself due to the inherent saturation limit of the soil. Holding part of the peak flow in storage reservoirs for regulated release is the most effective way for flood moderation. Easier said than done.
Many a time the areas under floods during the monsoon face a drought-like situation during long dry spells in a lean season. If flood storage is made an inbuilt component of all dam projects and a small portion of the net storage dedicated to drinking water and critical irrigation, alternating miseries caused by floods and drought can be effectively staved off. The planning strategy, therefore, should foster integrated planning and management of land and water resources of the basin through legislation.
Local decision-makers vis-à-vis implementing agencies must appreciate the scale and complexity of the river basin as a whole and evolve programs within its carrying capacity to fit in to the approved master plan. Clearance and coordination of projects of multiple agencies directly or indirectly involved with water resources in a basin may be assigned to an independent regulatory body comprising reputed professionals from different disciplines. All stakeholders and even co-basin states for programmes of inter-basin ramifications should collaborate to achieve the objective of holistic development and management of the water resources.
The writer is a former Chairman of the Brahmaputra Board (GOI)