Holden, P.B., Rebelo, A.J., Wolski, P., Odoulami, R.C., Lawal, K.A., Kimutai, J., Nkemelang, T. and New, M.G. (2022). “Nature-based solutions in mountain catchments reduce impact of anthropogenic climate change on drought streamflow.” Communications Earth & Environment, 3(1).
The study attributes a 12% to 29% reduction in drought streamflow in the mountain catchments supplying Cape Town to anthropogenic climate change, and models how far clearing invasive alien trees offsets it: 3% to 16% at moderate invasion, with a further 10% to 27% avoided by preventing full invasion. The wiki takes from it the framing of restoration value in drought-flow terms, which is the metric where water retention work has its strongest claim.