Where the heck is this Dwarven Storehouse I keep hearing about in "Eastern Skyrim"

Can someone please be more specific as to is location? I followed some instructions elsewhere that seemed to lead to this storehouse, and it just led me to Kagrenzel, the dwarven ruin with the light pedestal trap, and a huge fall into water at the bottom. That one didn't seem to have jack for dwarven materials unless I missed something.

More specific directions would be much appreciated. I'm trying to mine/gather dwarven materials.

I'm pretty sure that you are refering to Mzulft and the Dwarven Storeroom, just south of Mzulft, located along the easterly most edge of Skyrim. It is located along the easterly side of Eastmarch found on this map.

Edit: It should be noted that Mzulft is off limits (requires a key) until you receive a certain quest but the storeroom is open to the public.

While this doesn't directly answer your question, as I haven't yet heard rumors of a Dwarven "storehouse", I can tell you where to get a ridiculous number of Dwemer artifacts.

Nchuand'zel, the ruin beneath Markarth, is the richest I've yet found. To give you a sense of scale, I walked out of Avanchnzel with the materials to smelt ~100 Dwarven metal ingots. I have so far carried the materials for more than 700 ingots out of Nchuand'zel, and I'm not even sure I've gotten it all.

The spoils are split into two main areas — Calcelmo's Dwemer Museum, and Nchuand'zel itself. Both are accessible via Understone Keep in Markarth (you need to go through the Nchuand'zel Excavation Site to get to the city itself).

The ruin is populated primarily by Falmer, so is largely smash-and-grab. The museum is patrolled by guards who will attack you if you haven't obtained Calcelmo's permission and is a much sneakier affair.

If you fast travel to Mzulft the storeroom will be directly to your right when you load.