10 Challenges in upland watershed management

The paper proposes a green-blue water approach to watershed management, emphasizing that managing soil moisture (green water) can increase water productivity and reduce downstream scarcity. It examines the hydrological impacts of land-use changes, such as deforestation and afforestation, and discusses the use of Payments for Environmental Services (PES) to incentivize sustainable upland management. Case studies from the Jordan and Tana River basins illustrate the challenges of transboundary cooperation and the potential for 'soft-path' interventions over large-scale infrastructure.

• Conventional Integrated Water Resources Management (IWRM) often neglects 'green water'—water infiltrated into the soil from precipitation—focusing instead on 'blue water' (rivers, lakes, and groundwater). Because human appropriation of green water is nearly ten times greater than that of blue water, managing it can provide significant new opportunities to alleviate water scarcity, particularly in drylands.
• Land-use changes significantly alter the balance between green and blue water. Globally, deforestation and conversion to agricultural land have increased global discharge by approximately 1,700 km3/yr (about 5%). Conversely, afforestation can reduce downstream water availability because trees have higher leaf area indices, deeper roots, and no fallow periods, leading to higher evaporative losses.
• Climate change is projected to increase water stress through higher temperatures and variable rainfall. In Africa, a projected 10% reduction in precipitation could lead to drainage reductions of up to 50% or more, while groundwater recharge in parts of Africa and the southern Mediterranean could drop by over 70% by 2050.
• In the Jordan River basin, water scarcity is exacerbated by unilateral overexploitation and a lack of basin-wide agreements. While a multi-billion-dollar Red Sea-Dead Sea conduit is planned, the author argues that low-cost 'green water' interventions, such as rainwater harvesting and conservation agriculture, could more effectively increase water productivity and benefit the rural poor.
• The Tana River basin in Kenya faces acute scarcity and reservoir siltation caused by upland deforestation. The Green Water Credits (GWC) project promotes 'soft-path' solutions—such as conservation agriculture—as alternatives to 'hard-path' structural engineering (additional reservoirs), which fail to address the root causes of scarcity located upstream.
• Payments for Environmental Services (PES) can reconcile upland poverty with downstream water security by rewarding farmers for sustainable land management. This is particularly viable when downstream beneficiaries are economically strong, such as national hydropower companies or large cities, and can replace the need for continuous public funding.

APA

Hoff, H. (n.d.). 10 Challenges in upland watershed management. Stockholm Environment Institute. https://www.sei.org/mediamanager/documents/Publications/Atmospheric/challenges_upland_watershed_hoff.pdf

Chicago

Hoff, Holger. 10 Challenges in upland watershed management. Stockholm Environment Institute, n.d. https://www.sei.org/mediamanager/documents/Publications/Atmospheric/challenges_upland_watershed_hoff.pdf.

Wikipedia

{{cite report |last1=Hoff |first1=Holger |title=10 Challenges in upland watershed management |publisher=Stockholm Environment Institute |url=https://www.sei.org/mediamanager/documents/Publications/Atmospheric/challenges_upland_watershed_hoff.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{hoffndchallenges, author = {Hoff, Holger}, title = {{10 Challenges in upland watershed management}}, institution = {Stockholm Environment Institute}, url = {https://www.sei.org/mediamanager/documents/Publications/Atmospheric/challenges_upland_watershed_hoff.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }