Includes Reference

This study investigates the environmental impacts of sand dams on biodiversity and
ecosystem services along the Kikuu River in Makueni County, Kenya, an arid and semi
arid region where water scarcity and food insecurity remain critical challenges. While
sand dams are widely promoted as sustainable water management interventions, their
ecological effects on biodiversity and ecosystem services are less documented compared
to their hydrological benefits. Addressing this knowledge gap, the study aimed to
evaluate how sand dam construction influences plant and animal diversity as well as the
provision of ecosystem services in the Kikuu River system. The research was carried out
between 2023 and 2024 and covered a 35 km stretch of the Kikuu River, where 21 sand
dams were identified. A total of 306 households were sampled. Data collection involved
mapping natural (e.g., Acacia species, xerophytic grasses) and human-made features (e.g.,
water pumps, roads), biodiversity surveys of plants and animals in both sand dam and
control sites, and household interviews on ecosystem services. Sampling methods
included perpendicular transects, spot checks, and sweep counts. Data were analyzed
using Welch’s ANOVAwith Games-Howell post-hoc tests, Pearson Chi-square tests, and
regression analyses. The results indicated that sand dam sites supported higher plant and
animal biodiversity compared to control sites without dams (p < 0.001). For instance, the
Kwa Moses and Mbukoni dams demonstrated rich vegetation cover and increased animal
presence, while regression analysis revealed that sand dams had a positive and
significant relationship with ecosystem service ratings, particularly in water provision,
irrigation, and soil stability. However, variations in performance among dams highlight
the influence of design, location, and maintenance. The study concludes that sand dams
significantly enhance biodiversity and ecosystem services in semi-arid landscapes but
require site-specific management strategies, continuous monitoring, and design
improvements to maximize benefits and reduce ecological trade-offs. It recommends the
strategic expansion of sand dams, coupled with community participation and post
construction monitoring, to strengthen ecological resilience and sustainable development
in water-scarce regions.