###### Abstract  
The damming of watercourses results in sediment accumulation and, therefore, in the reduction of useful storage capacity. The storage capacity can be recovered through dredging, but this process generates large volumes of sediments that require proper management. To avoid landfilling and promote recovery operations, sediment characterization is the preliminary step to any assessment and decision. This paper presents the results of tests on sediments sampled at two reservoirs in southern Italy, the Camastra and the San Giuliano, in Basilicata. These investigations include testing of organic matter, heavy metals grain size distribution, and the assessment of the pollution degree. A lack of correlation between the sampling point and the heavy metal content was observed in sediments, except Be, Cr and Ni for the San Giuliano reservoir. This may be attributed to the presence of agricultural activities and fertilizer use in its watershed. Similarly, there is no dependence between the organic carbon and the grain size distribution, the former being scarcely found in both reservoirs (on average 0.91% for the Camastra sediments and 0.38% for the San Giuliano sediments), the latter being predominantly characterized by sandy matrices downstream of the reservoirs (on average 64.3% \(\pm\) 32.9%) and by silty-clayey matrices in the upstream areas (on average 65% \(\pm\) 14.3%). Finally, the determination of the single pollution index \(\mathrm{P_{i}}\) and the Nemerow integrated pollution index \(\mathrm{P_{N}}\) highlights that sediments are not contaminated with heavy metals. Most of them show values of the indices above between 0 and 1 (\"unpolluted\") and, in a few cases, values between 1 and 2 (\"poorly polluted\"). The findings suggest that these sediments can be reused for environmental and material recovery, using them as secondary raw materials for sub-bases and embankments, for filling in disused quarries, for reproffiling and reconstructing the morphology of coastlines or riverbeds, for beach nonishment and in the agronomic and construction industry fields. s 2024 14 727  
and reducing, over time, the useful reservoir capacity due to an upstream area with reduced velocities [6; 7; 8; 9; 10]. This capacity may be sustainable or exhaustible, depending on whether sediment management plans are established, and recovery measures are implemented [11; 12]. In this regard, the strategies currently employed to accept the phenomenon of sediment accumulation passively are not sustainable in the long term [13; 14]. The aim, on the contrary, should be to achieve a balance whereby, in addition to accepting that part of the usable capacity is taken away, thresholds should be set, at which the breakthrough processes are initiated [15; 16]. The volume recovery operations, functional to maximize the water holding capacity of the reservoir necessitate the removal of sediments deposited at the bottom of the reservoir. However, the challenge of disposal remains, since dredged sediments are classified as waste. Italian legislation, however, in agreement with European directives, allows alternative options if it is guaranteed that the sediment, in being reused, does not present a risk to each of the main ecosystem components [17]. Characterization of the dredged sediment becomes essential, i.e., defining a complete set of analyses that provides the necessary information to determine the reuse of sediments. It is possible to propose and verify the compatibility of sediments for environmental recovery, to use the dredged material for nourishment of coastlines and sandy shores, for filling disused quarries or for making road embankments and subgrades, and for material recovery, especially in those production sectors with the most significant environmental impact, such as agriculture and the building materials industry [18; 19]. Therefore, it is essential to define its physical, chemical, and mineralogical properties, to assess its compatibility for reuse in the construction materials field [20; 21; 22; 23; 24].