The Lethbridge Northern Irrigation District (LNID) was formed in 1919 and as of 2019 consists of 188,465 irrigation acres of land on the north side of the Oldman River, between Fort Macleod and Turin, Alberta.
Construction of the water distribution system and Keho Lake Reservoir were completed in 1923, but the diversion works were destroyed that year in an unprecedented flood and had to be rebuilt. Park Lake Reservoir was added to the system for additional storage in 1930. Originally managed by elected Trustees, the District was administered by a Provincial Government Trustee from 1926 to 1968. An elected Board resumed management in 1968.
In 2010, the water users approved an expansion plan in the District from 177,000 irrigation acres to 227,000.