If there are multiple consequences from one act, some of those consequences may be desirable and some undesirable. It would be wrong to call all of them the “intent”. That us why they are called “unintended consequences”.
I used unintended in the sense of unexpected, not unwanted. Yes, many actions would be expected to have both good and bad consequences, but if we intentionally commit an act with the expectation that it will result in a bad consequence it seems hard to argue that we didn’t intend that consequence, whether or not we desired it.
It’s been pointed out already.
All the foreseeable consequences are not intended. We don’t set out to achieve them all. In acting, we may accept consequences, but that is not to intend them. As you know, to intend harm condemns an act (as immoral), whereas if a harm is not intended but foreseen, the act may be acceptable (moral) according to the balance of consequences (assuming of course a good object). If the balance is not favourable, the act is immoral.
Circumstances - the balance of consequences - may make an otherwise good act evil.
Certainly whenever an actor chooses a path where bad consequences outweigh good (and he knows he does that), he does wrong. In some cases, his failing is in an unreasonable weighing - perhaps failing to give various factors appropriate moral weight - be that an honest error or a willful glossing over the inconvenient. Church social teaching often tries to illuminate what should be the proper assessment.
