Since the end of past century drought phenomenon has spread severely over many of regions in the world, included Middle East Region. By reason of this, Iran Government has constructed four water projects on the Lower Zab Riverbed, three of them are dams tor store water, their names are;(Grzhal, Brisoo, Kollasa) , the fourth also is dam its name is(Kany-Sew) but for changing the canal of the river and transporting a part of its water to Urmia Lake, on the pretext of rescue the lake from drainage. These four projects can keep (3.505m3) of the river’s water, therefore, become a serious danger on the water resource inside Kurdistan Region and Iraq, will threaten drinking water of hundred thousands of families. About (500) hectares will lose their ability to plant agriculture especially in the Summer, will change the environment of the area….etc. The Iraq and Kurdistan Region authorities must face this action of Iran outside and inside, outside through diplomatic dialogues and resorting to international laws, and inside through construction of small dams, recycling sewage water and using water scientifically and economically….etc. According to the international laws the Tigress and the Euphrates and their branches consider as international rivers, therefore; Iran and Turkey don’t have right to construct dams on those rivers and do harm to water resource of Iraq and Kurdistan Region, even must divide the water of these rivers between these countries reasonably and fairly.