Because the land at the upstream part of the Lele is broad, and rather remote, academic institutions have not done any fundamental surveys or evaluations of the natural resources in the area. Often the operators first begin mining, and only then does the PBM bring someone in to do an assessment.
由於樂樂溪上游地偏路遠，過去學術單位幾乎未對此地的自然資源做過基本調查與評估報告，往往是業者先自行探礦，再由礦務局請人評估。