Your sentence is great, and since the risk is already there, because the authorities haven't intervened yet, you may even say: "Hay riesgo de tragedias si no se atienden doce quebradas".
Still, both "habrá" and "hay" may be read as an assertion that there is negligence from the part of the people charged with the safety of the region. Diplomacy first.
If you want to keep both strict grammar and diplomacy, you may say: "Puede haber riesgo de tragedias, si no se atienden doce quebradas". There, the problem for newspapers is that long sentences must be avoided.
