Creation is filled with signs that tell of the goodness and generosity of its Creator, and it is hence a sacred space: respecting it is akin to charity (sadaqah) or invocation. One day, as the Prophet, peace be upon him, passed Sad ibn Abi Waqqas, who was performing his ritual ablutions, the Prophet said to him: "Why such waste, O Sad?" "Is there waste even when performing ablutions?" Sad asked. And the Prophet answered: "Yes, even when using the water of a running stream." [Ahmad, Ibn Majah]
Water is essential element in all the teachings and ritual practices, for it represents the purification of body and heart, of physical outwardness as well as spiritual inwardness. But the Prophet taught Sad and his other Companions never to consider water, or any other element of nature, as a simple means towards their spiritual edification; on the contrary, respecting nature and using it moderately was already, in itself, a spiritual exercise and elevation, a goal in their quest for the Creator.
"In The Footsteps of The Prophet" - Tariq Ramadan, p. 202