Assessment of the flood risk reduction in the Jalalabad area due to the proposed large dams in the headwaters of the Kabul River Basin

The city of Jalalabad is located in eastern Afghanistan along the Kabul River. Fed by the Kabul River Basin, the river flows through this major city as well as large amounts of agricultural land, and deposits into the Indus River after crossing the Afghanistan-Pakistan border. The Kabul River is particularly dynamic and sees regular flooding events during spring freshet that impact the city of Jalalabad and the surrounding agricultural land. The Afghanistan government currently has a proposal to The World Bank requesting financial support for the construction of 14 new large dams. These dams will aid the existing 3 large dams in the Kabul River Basin with flood mitigation for the watershed and geomorphic stability of the Kabul River. The purpose of this research is to illustrate how the addition of these dams would benefit the cities, rural communities, and the agricultural industry along the Kabul River during large flooding events. Using the calibrated USDA Agricultural Research Service (USDA-ARS) Soil and Water Assessment Tool (SWAT), the flood flows for the Kabul River were determined for the 2 to 100-year flood events for both the existing and proposed series of large dams' scenarios. Using the US Army Corps of Engineers River Analysis System HEC-RAS we ascertained the extent of the flooding into the city and the surrounding area. Finally, using the US Army Corps of Engineers Flood Impact Analysis (HEC-FIA) model was used to determine the agricultural, economic, and social consequences to the city and surrounding lands. The results from this model illustrate how critical the proposed dams are in protecting the city of Jalalabad and its residents. Similar methods can be used in this data-scarce part of the world to assess the reduction of flood risk for other cities and rural communities within the Kabul River Basin, including the capital city of Kabul in Afghanistan and the Charsaddah and Nowshera regions in Pakistan.