*3.1. Environmental Impacts*

The results from the questionnaires showed that 20% of governmen<sup>t</sup> administrators had once received letters of complaint related to dry watercourses caused by SHPs from local residents. This ecological impact was evidenced by governmen<sup>t</sup> reports, with more than 93% (5815) of the projects resulting in dry reaches accounting for a total length of 7508.5 km, and around 7% (430) of the projects cut flows of up to at least 3 km of dry reaches (Figure 1).

**Figure 1.** Lengths of dry reaches (dr.) generated by small-scale hydropower projects in Fujian Province. Source: [46].

In addition to dry river reaches, the excessive construction of SHPs in Fujian Province had turned some river reaches into reservoirs. Data collected from the Fujian Provincial Department of Water Resources show an average SHP spacing of 13 km on 65 rivers with a drainage area > 500 km2, which has resulted in large decreases in discharge and flow velocity, which is conducive to algae growth. For example, on the Jiulong River, 10 SHPs operate on the trunk reach with an average spacing of <7 km and the smallest spacing of just 5.4 km.
