Water on Mars or What?

This picture, taken by Viking Explorer, reveals erosional channels in the northern lowlands of Mars. One article on this topography said the erosion was similar to that found in the scablands of Washington State. We know the scablands were formed by water. Where did this Martian "water" come from?

A further note on Martian features: It seems that the canals once "discovered" on Mars that gave rise to so much speculation about a long-gone civilization were simply artifacts of the telescopes used at the time. In other words, the canals never existed. What does this say about the nature of scientific investigation? Extrapolation on the basis of conjecture or enthusiastic guesses often leads the unwary public astray. Happily, in this example of the nonexistent canals, scientists have acknowledged their error. This is honesty that should be commended. One of the main problem is, however, we laity of science may go for decades without checking up on what is true and what has been debunked. Science has the obligation to inform us as fervently about errors as it misinforms us in the first place.

Far as we know, based on our trust that the above is a real picture of the northern lowlands of Mars, an enormous area has been guttered by some liquid substance, perhaps water.