I have been following the situation in Alberta and I feel horrible that all of you are having to deal with this.
This is not the first question of this nature that I have seen and it is a very fair question, from either a landlord like yourself, or the tenants.
In this case, the circumstances, beyond the control of either yourself or the tenant, has prevented your rental property from being habitable for a period of time. Accordingly, the rental agreement becomes frustrated, as you are no longer able, for the time being, to fulfill your end of the agreement, in that you are obligated by contract to provide a rental dwelling to this tenant.
In the case of high density rental units, such as high rise apartments, the landlords are able to move the tenant into a new unit in the building if their unit becomes uninhabitable for whatever reason. By doing so, the agreement is not frustrated and can be fulfilled, and the obligations on both sides continue.
At this time however, you are not able to uphold your end of the agreement, unless you had another unit for them to occupy temporarily and the tenant must find alternate accommodations at present. Accordingly, the courts would not expect them to pay for your rental unit, during a time that it is not available, through no fault of either you or the tenant.
Most policies of insurance carried by landlords on their rental properties will also cover any loss of rental income as a result of situations such as this. I would suggest that you contact your insurer and determine if you have such coverage. If the unit is covered for the damages that have occurred, and the insurer is aware it is a rental property, then you should have coverage for loss of use.
This is similar to the provisions which would see you reimbursed for having to seek temporary hotel accommodations if your own residence were damaged by fire, flooding etc.
The only loophole through which you may still be able to receive the rent payment, is if the tenant has their own separate policy of insurance on the rental property, outside of the typical "content insurance" which covers them for their living expenses while not able to occupy the rental property. If they were being reimbursed and were not out of pocket, it is could be reasonable to ask for payment of the rent. However if your insurer were to reimburse you for the lost income, it would be improper and potentially fraudulent if you were to try to "double-dip" and profit by being paid both by the tenant and the insurer.
Please let me know if you have any further questions or require clarification as I am happy to continue discussing this.