Kathmandu, April 23 The Ministry of Federal Affairs and Local Development has directed the Kathmandu Metropolitan City, Lalitpur Metropolitan City and all municipalities in the Valley to collect accurate and authentic details of drainage systems connected to rivers , including the Bagmati River, Tukuche Khola and Hanumante Khola, by households, offices and industries without treating the wastewater. According to a letter issued by Environment Management Section of the MoFALD to the local levels today, they shall develop and implement an action plan on the basis of the details. The local levels will coordinate with the Ministry of Urban Development and Ministry of Industry to put in place the action plan. Earlier, the MoFALD had directed the local levels to strictly prohibit solid waste disposal, and discharge of sewage and untreated wastewater into the river system. According to the Basic Standards on Settlement Development, Urban Planning and Building Construction-2015, a house or building constructed in municipal areas must build at least one attached septic tank as part of urban sanitation. They were also told to deny construction completion certificate to any house that does not have an attached septic tank. The untreated sewage, wastewater and toxic waste produced by houses, industries, hospitals and offices in Kathmandu flow directly into the rivers and streams, polluting the environment. Increasing degradation of the Bagmati River Basin has been evident in recent years due to rapid urbanisation and population growth. Uncontrolled disposal of untreated wastewater (domestic, industrial, solid waste and agricultural runoff) in the rivers has far surpassed the assimilative capacity of the river, according to various studies. They have reported that water of the river system in the Valley is of very poor quality and unsuitable for any freshwater fauna and flora for most of the dry season. The water quality, in the rainy season, however, improves considerably due to the increase in the assimilative capacity of the river.