How many meters of Liaohe main stream can't have overseas housing?

There shall be no housing outside the main stream of Liaohe River 10 to 30 meters. According to relevant public information, it is forbidden to build houses within the slope line managed by the government and within 10 to 30 meters outside. Because of the different management scope of rivers in counties and cities, people want to build houses near rivers, and they need to consult relevant departments in advance and get the approval of relevant local departments before building houses.