My home course in my youth had a width of rough next to the fairway that was maintained and irrigated, beyond that it was not irrigated, turf was spotty but mowed, and you could have a hard pan lie. It was ideal. If fairways are wide, there is little need for irrgated rough, maybe 10 feet of fescue that is mowed, then beyond that have fescue, no irrigation, but mowed. That way you get those tight lies, possibly on hard pan between clumps of grass. That is rough. Searching for balls in tall grass is not right. Bluegrass should be banned from golf courses.
This approach makes real rough, plus irrigation demands are reduced. Irrigation materials and installation costs are more though. A line of heads must be placed along the edge between the 10' of primary fescue, and the secondary fesue. That way the secondary can be grown in, afterwards the heads are adjusted to half heads so only the primary rough and fairway receive irrigation.
The fesue works well because it does not perform ideally in traffic so it can be stressed in areas, again making real rough, making for some bad lies, but at least you can see the ball, and put the clubhead on the ball, but it may be on hardpan. The secondary rough fescue is established, it is mowed to keep a reasonable height, but receives no fertilizer, no water, no chemicals other than to treat weeds initially. It makes for difficult, but honest lies, not lies in knee high grass