How to fly LOC approach when IAF is a specific DME from LOC, but LOC has no DME?
You have a few different points here but the short version is: IWA is a VORTAC and I-IWA is a localizer, i.e. they're different navaids. DME is available from IWA and it's optional but not required for the I-IWA localizer approach. If you do have it, you can use it to identify the ORIYE fix and use the lower minimums at the bottom of the plate, e.g. 1800-1 for category A. If you can't identify ORIYE, you can only go to the regular minimums of 1940-1.



First, I suspect you're confusing I-IWA (a localizer) with IWA (a VORTAC) but they're different navaids that use different frequencies, as shown on the chart. The I-IWA localizer provides lateral and vertical (glideslope) guidance but not DME, which you get from the IWA VORTAC. If you don't have a DME receiver, you could use an IFR-certified GPS instead. 

Second, if I understood your question correctly about approaching from the northwest, you're asking how to identify SNOWL without using DME. SNOWL is an intersection ("SNOWL INT") and you can identify it using VOR only, by finding the intersection of any two of these radials:


IWA radial 122
PXR radial 109
TFD radial 028


Third, as far as I can see from the plate, DME is the only way to identify ORIYE (remember that you could use GPS instead of an actual DME unit). When you look at the minimums at the bottom of the plate you can see that the regular category A localizer minimums are 1940-1 but there's an extra set of minimums that you can use if you can identify ORIYE and they let you get lower, to 1800-1. In other words, if you have DME then you can use it to identify ORIYE; if you don't, you ignore ORIYE. Either way, you still have to use the correct set of minimums.

Finally, SNOWL is 6.4 DME from the IWA VORTAC, but only 5.8 DME from the "airport profile" (see the chart legend), i.e. the runway. That means, the runway end is 0.6 DME from IWA (that distance is also shown on the profile).