As discussed in some previous posts on "qochas", these structures had and have an agricultural function. Some qochas had a ceremonial use too. At Rodadero (Cusco) we find the huge Qocha Chincanas.
Near the parking of this archaeological site, where it is placed the statue of the White Christ, the satellite imagery (Google Maps) shows two radial/circular structures as those used for agricultural purposed near Titicaca lake.