Ummm... I know I am gonna take flack yet again, but...

Gutters do NOT cause ice dams. Ice dams are caused by improperly installed insulation and/or lack of insulation and/or lack of ice dam protection under the shingles.

Gutters may be used to collect rain water. They may also be used to keep water off walkways and steps to help prevent people from slipping and falling. As well, they may also be used to direct water away from building foundations to help prevent basement leakage and to help preserve the foundation integrity.

Gutters are good.

Check out CMHC, LH.... I am sure there's info on the above.