Lightning Bolt restores mana equal to 40% of the damage you deal, as a Resto Shaman.
So you could likely include a bunch of Lightning Bolts, as the timer mechanism controlling how often you cast your heals.

I might go with Earthshield,Null and a reset=combat/alt.
That way you can force it to recast, but otherwise it is a full Earth Shield at the start of every fight.

If you're spamming the macro, then the number of GCD's (ie, spells) would likely get you a Chain Heal towards the end of the Riptide; err a bit early, so you get the bonus for sure.