 The International Boundary Wastewater Treatment Plant (IWTP) developed, as a joint project of the USA and Mexico in the mid-1980s following substantial environmental studies, treats 25 million gallons of water per day (mgd) from the Tijuana River; directly pumped across the border from the central collection point in Mexico.When the river is flowing, the diversion system of the plant begins operating and diverts up to about 12-13mgd to the IWTP.The total amount of water being diverted must not exceed 25 mgd, based on a monthly average decided upon by permit conditions, although the IWTP can treat sustained flows up to 45mgd daily and peaks of 70mgd for a short period.