This probably happens almost everywhere, but I'm noticing it more here lately.
Committees are supposed to come in two flavors: 'standing' and 'ad hoc.' (The same is supposed to hold true for subcommittees.) Standing committees exist for their own sake, and they're built for permanence. Locally, for example, the curriculum committee is a standing committee. It isn't going anywhere, since nobody anticipates abandoning curriculum. Standing committees typically have membership based on 'representation' of various parts of the college, with the idea that every affected area should have the opportunity for input.
The strength of a standing committee is typically a relatively clear charge, and a relatively clear place in the college. We know what the curriculum committee is supposed to do, where it 'reports out,' what its deadlines are, and where it's supposed to get its membership. The weakness is that long-standing committees are subject to capture by a few strong personalities who make them into their personal fiefdoms. When a committee has a chair-for-life, it's unlikely not to fall victim to certain predictable pathologies.
Ad hoc committees, as the name implies, are constituted to address a particular issue. In the best cases, the issues they address are temporary, so the committee can dissolve itself when the issue passes. Self-studies are like that, and so are groups to address, say, the design of a new building. Once the visiting team has left or the building has opened, the committee has lost its reason for being and can disband. In my very limited observation, ad hoc committees tend to be far more effective than standing committees, if only because they're more concerned with problem-solving than with representation. Of course, your mileage may vary.
Then there's the weird third category. These are committees that are formed to address ongoing concerns, but that aren't given 'standing committee' status. Locally, an example might be a committee within the English department that addresses issues with developmental (remedial) English courses. I don't expect remediation to go away anytime soon, but the committee's focus is too narrow to warrant 'standing' status. Instead, it's a sort of hybrid.
Hybrid committees come from every-which-where, and frequently bump into each other as they (inevitably) recognize that their issues overlap with other areas of the college. To stick with the remedial English example, it didn't take them long to figure out that they needed to address ESL, ADA/Learning Disabilities, registration, Academic Standards, developmental math, high school outreach, new student orientation, and so on. And their forays afield inevitably bring cries of anxiety from other committees and areas of the college, each jealous of its own autonomy.
Worse, some of these hybrid committees have been supported with (limited) release time at their formation, out of a sincere sense that their initial charge was important. So folding committees into each other, or disbanding those that have outlived their usefulness, becomes a collective bargaining issue. ("Why are you taking away my release time?" As if the release time belonged to the person, rather than the position.) The easy response to inequities is usually to bring up the lower party, which involves…wait for it…creating even more committees with even more release time, so nobody gets more than anybody else.
(The more difficult response is to simply shut down or consolidate the past-their-prime committees, and use the freed-up resources to address other issues. It's the right budgetary move, but the internal politics are often bloody. Folks who lose their sinecures can be very quick to put the worst possible light on any change.)
I'm beginning to suspect that part of the reason so many admins like to do reorganizations is that they're often the only politically-palatable way to put zombie committees out of their misery. Pick on one or two committees, and you have an anti-(fill in the blank) agenda. Pick on a dozen and start a few new ones, and you're just doing another re-org. I'm not a fan of re-orgs generally, but they can serve a purpose.
Committee creep – both the Incredible Growing Mission and the sheer number of committees -- is insidious, and remarkably hard to stop.
Wise and worldly readers – has your college or organization found a sustainable way to keep committees reasonably close to their purposes?