You should re-apply for the form. It is stated on the checklist, though, that you do not need to re-submit original IELTS anymore, but I've heard stories where people got their applications returned precisely because of this reason, despite the fact they were doing re-application
You can probably do is write a long cover letter, explaining that they already have your valid score card, and according to the checklist, you need not submit no more if they already have it, but IMO the best is to re-apply for the form, then send the original along with the applications. Hopefully this won't delay your applying too much (it can take three weeks just to get the score card from them).
EDIT: the official position of CIC is that you do NOT have to re-submit the original, just the copy is enough
But make sure you include at least a copy of your score card, and write an explanation (on the front, maybe, with big letter) that they are in possession of your IELTS score card. I'm still of the opinion that you should try your best to obtain the original, unless if it will significantly delay submitting your application.