This is an example of what can happen on a two story house that doesn’t have rain-gutters installed. The water falls from the second story roof and splashes back against the wall. If this happens during a heavy or long rain. Eventually the water will work its way through the stucco to the lower part of the the wall below the patio cover. You can tell in the picture that this doesn’t look great. One way to avoid it is by installing a rain-gutter on the second story fascia board. Any good installer can do this from the roof if the patio is already installed. Just remember that this is not a leak, I would consider a leak something that drips or gushes water. When the water makes it around stucco like this it is because stucco is porous and can only take so much water before it looks damp and wet. If you compare the stuck under the patio near the ground to the stucco at the bottom right of the picture you can see that wear there is water you will see dam darker stucco.
One thing to cheer you up is that it is sunny almost 95% of the time in Southern California, so if you don’t have the money for rain-gutters this is only an aesthetic problem that can be ignored until it is sunny again.
If you live in the Inland Empire we highly recommend AC Superior Rain-Gutters