It's hard to tell from that angle. Could be a sheath...the end-on view will tell you. If it opens in a V shape, it's another leaf. If the end-on view is just a single edge then it's a sheath.
Yours may be a Catt that forms a bud within the sheath immediately, or it may want to rest for a few months before buds form. Once you see buds forming inside, however, up the water a little bit.
Good luck, Tmai!