This is being planned in Tamil Nadu, India. The reason is that traditional mosques don't allow women to attend the jamaat (citizens' council) which is always attached to a mosque and which makes judgments on the domestic affairs of the community, including domestic violence. This means that a woman claiming that she is a victim of domestic violence cannot be present when her case is decided.
How will this plan fare? Here's one problem:
According to the Muslim Public Affairs Committee, male-controlled jamaats are stating that "women should have the right to offer prayers in mosques. In at least five percent of Tamil Nadu's mosques there are separate enclosures for women. But a women's mosque is unacceptable."