Kaunas Reservoir, the largest artificial body of water in Lithuania, has been characterized by active coastal erosion processes since its formation, which are currently exacerbated by more intense precipitation, water level fluctuations, and recreational use. The aim of the study is to assess the condition of the Kaunas Reservoir shores and to determine the differences in erosion intensity in different sections, linking them to slope gradient, vegetation cover, and recreational activity characteristics. The research was conducted at three study sites (1–3) along the coast; at each site, the height of the shore, slope gradient, vegetation cover, signs of erosion, and recreational load were measured in ~50 m sections (GPS coordinates, photo documentation). The highest vulnerability was found at site 1: slopes were 2.6–5.6 m, gradients were often >30° (up to ~42°), vegetation cover was 11–28%; 5 out of 10 sections were classified as class 3, the rest were identified as class 2. In the third location, the banks are stable: low to medium (slopes 10–20°), cover 68–85%, the shore is protected by continuous strips of reeds; all sections are class 0–1. Class 1 prevails in the second location (80% of sections), while class 2 is recorded in only two locations, where the cover has decreased to ~56–58%, the slope is ~19–19.5°, and the height is ~2.4–2.5 m. A pattern emerged: when the slope is >30° and the cover is <30%, there is a transition to class 3; when the slope is <20° and the cover is >60–65%, the classes that remain are usually 0–1. Recreational activity (informal access paths, campfire sites) acts as a catalyst where the cover has already weakened. It is recommended to apply combined measures in the first place (bank toe protection, biotechnical slope reinforcement, sowing and mulching, surface water drainage, access control), local restoration of the cover and closure of unofficial access points in the second place and thirdly a conservation regime, preserving the integrity of reed beds and avoiding new access to water. Regular monitoring (≥2 times per year) would allow to distinguish episodic hydrometeorological impacts from constant recreational loads and to assess the effectiveness of the applied measures.