Glendenning, C.J. and Vervoort, R.W. (2011). “Hydrological impacts of rainwater harvesting (RWH) in a case study catchment: The Arvari River, Rajasthan, India. Part 2: Catchment-scale impacts.” Agricultural Water Management, 98(4), 715-730.
A catchment-scale study of the johad network in the Arvari, the river whose revival is the best-known case of community water harvesting. Recharge from the structures was about 7% of rainfall; past a threshold area, further structures added nothing to groundwater stores and reduced stream flow. The wiki cites it as the main caution for retention programs in over-allocated catchments, where downstream users and regulators measure flow.