Splash has water cannons. If you make a quick stop by the viewing area, you can see if the cannons are on or not. You can't actually see the cannons from the bridge- they are designed/timed to look like a big splash that just happens to spray the (other) passing logs. The water cannon spray goes towards Pirates.
Kali is also a bit hit or miss. More or less, everyone gets (at least) a few sprinkles. Often that's all you get. Sometimes, one side of the raft (=2 riders) gets soaked, sometimes 4 riders get fairly soaked.
There's a bridge near the end of the ride, and people on the bridge can push a button to operate sprayers, that might also hit your raft such that you get wet, but not always.
I don't know how to say this, but if you don't like getting wet, WDW might not be the best destination. When I think back on my trips to WDW and all the times I've been (very) wet, RAIN is by far the most frequent culprit. Like anywhere, FL rain is variable. It can be light, but FL is also known for heavy downpours, especially in summer/fall. Even when it doesn't rain, Florida heat can often be sticky. If you tend to sweat, you might feel like you were out in the rain.
It pays to watch the daily weather report, and to pack with the idea that it might rain. most of the year, I like to bring something like water-tolerant walking sandals and clothes that can get wet. Generally though, I'd suggest dressing and planning for potential pop up storms most days of your visit.
If rain risk is below 50%: maybe wear sneakers, plastic poncho, denim.
If rain risk is above 50% and Kali days: I wear water-tolerant hiking sandals (or similar), avoid denim, avoid white (i.e. sheer when wet white), and bring a rain jacket. For WDW, I LOVE my 'packable' rain parka.
'Packable' rain parkas are sold in a number of stores, under assorted names, but an easy one to find are the ones sold by Uniqlo. These little jackets fold down into one pocket, so they are compact, lightweight, breathable. Many other big name chains sell them seasonally, and they come in all ages/sizes/genders.
Plastic ponchos vary in quality and price. Before they are opened, ponchos are very compact, but ponchos can also be pretty miserable to wear, and re-folding them can be a pain. I almost always pack a few, but rarely use them.