It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "None of you should urinate in standing water, nor perform the ritual bath for janabah in it."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1128