Work Package 2 – Environmental flow assessment and tool development

In order to preserve aquatic biodiversity and existing natural ecosystem services, flow releases must be an integral part of reservoir and dam design and operations. Environmental services need to be included and quantified (and when possible, monetized) at the planning stages rather than when these dams have already been constructed, if efficient outcomes are to be realized.

This work package will incorporate ecosystem services (including community cultural and religious benefits – normally ignored, disaggregated by social groups, e.g. gender, ethnicity, caste, etc) provided by rivers – into the environmental flow (EF) assessment process. It will develop concepts and pilot tools for quantification of environmental thresholds for both surface and groundwater. It will be carried out at the scale of the entire Nepal, with in-depth study in western Nepal. The work package will explore the opportunity to put guiding principles and policies for environmental water allocations into place as a precautionary measure – prior to major water resources developments in the Country. It will analyze what needs to be done in terms of the institutional and policy context in an effort to integrate EF into water management policies. It will develop national capacity in EF so that scientists, policy makers, hydropower and irrigation developers and other key organizations are more cognizant of the importance of ecosystem services and also knowledgeable about how to enhance sustainable river basin management.

IWMI in partnership with WWF-India also conducted a comprehensive e-flows assessment in the Ganges in India (Sapkota et al., 2013). A similar comprehensive EF assessment through a multidisciplinary, multi-stakeholder approach will be conducted also in Nepal. Rivers will be classified according to typology and linked to indicator species, livelihood/cultural requirements and a monitoring plan.

IWMI has developed hydrology-based EF calculators for the entire Globe, Ganges Basin, and Sri Lanka (Smakhtin et al., 2008). These tools vary in detail, data requirements, stakeholder involvement and delivery (on DVD or on line). A similar concept will be applied and specifically targeted for Nepal. Under the proposed project, the functionality of the calculator will be extended to include ecological, biodiversity, social/cultural and religious components. 


  • Review of existing environmental flow assessment methods.
  • Develop an agro-ecological zoning plan for the study basins.
  • Apply and improve existing biotic index tools to assess the ecological status of the river.
  • Develop an inventory of livelihood, and cultural/religious benefits from the river for inhabitants of the basin disaggregated by gender, ethnicity, class, caste and religion.


  • Review paper on environmental flow assessment methods which specifically incorporate ecological/cultural information into environmental flow assessments. A peer reviewed paper will be submitted by January, 2017
  • ‘Environmental flow’ zoning plan for the study basins are developed, based on agro-ecological zones or other divisions. The desktop environmental flow calculator will use this zoning plan to base its environmental flow estimates in conjunction with river basin boundaries. The task will be completed by December, 2016
  • An inventory of the bio-indicator invertebrate taxa to serve as control for different conditions during the dry season, monsoon and post monsoon. The work will start in the monsoon, 2016
  • Recommendations for explicit consideration and inclusion of livelihoods, and cultural/religious needs into water allocation planning, as well as the conservation of the natural ecology of the river. The task will be completed by March 31, 2016

Assumptions and risks

  • Proper sampling methods used, and sampling performed incorporating different seasons (at least four), different anthropogenic conditions (water uses), and at least two activities such as abstraction and no abstraction conditions.
  • Adequate samples collected and taxonomy of the identified specimens known.
  • Respondents representatively selected and unbiased responses received.

Project outcomes

The information and tools developed by the project are used by river basin managers and contribute to making environmental flow allocations a standard practice in river basin management.

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