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.. The first official floodplain map was adopted by Ordinance 3701 on April 6, 1971. The map contained detailed information for Boulder Creek and South Boulder Creek from a study by the U.S. Army Corps of Engineers and estimated floodplain limits for the tributaries determined by Wright-McLaughlin Engineers. Ordinance 3927 created the Storm Water and Flood Management Utility on August 21, 1973. The utility provides storm water and flood management services by means of an enterprise. The enterprise is funded with monthly utility fees and development initiated plant investment fees. In the two years following, City Council adopted revised floodplain mapping for Boulder Creek and a new floodway definition. The floodway was defined as those areas in the floodplain where flows are two feet per second or greater, depths are two feet or greater, or to the point beyond which full encroachment into the floodplain from its edges would raise flood elevations by more than 0.5 feet. A prohibition of new residential structures in the Boulder Creek floodway soon followed. However, no prohibitions were applied to the tributaries since the floodway had not been defined for these areas. On October 8, 1973, the Boulder Creek Subcommittee on the Corps of Engineers Committee on Environmental Planning (CECEP) presented City Council with a nonstructural improvements policy for Boulder Creek, entitled the Flood Control Plan - Boulder Creek. Nonstructural improvements for floodplain purposes means methods that do not involve structural changes or channelization of the main creek, except for limited structural features such as bridges at roadways. City Council adopted the plan by Resolution No. 141 as "Nonstructural Flood Control Policies for Boulder Creek" on August 20, 1974. This policy has been implemented through preservation and restoration of the Boulder Creek greenway, through acquisition and removal of high hazard structures (such as the recent acquisition and removal of the 299 Arapahoe, 20-unit apartment building at Eben Fine Park), through construction of flood barriers (including the Canyon Point levee along Canyon Boulevard and Crossroads floodwall), through elevating and flood proofing buildings, and through grading modifications outside of the riparian creek corridor (Boulder Creek Acquisition Project at Boulder High School). Viele Channel was the first major drainageway improvement to be realized. It was completed in 1976 and extended from Viele Lake to its confluence with South Boulder Creek. The channel was improved in such a manner that it was believed to have removed south Boulder's Keewaydin and Frasier Meadows neighborhoods from the floodplain. The work was funded with the DDFCD. In 1977, the U.S. Army Corps of Engineers completed a study entitled the Metropolitan Denver and South Platte River and Tributary Study. The study provided a reanalysis of the Boulder Creek hydrology, increasing the 100-year flood discharge from 7,600 cubic feet per second to the current 12,000 cubic feet per second. Boulder joined the National Flood Insurance Program (NFIP) in 1978. The NFIP is the Federal Emergency Management Agency (FEMA) program that enables property owners to purchase flood insurance in communities that agree to implement measures to reduce flood impacts. Required measures include adoption of a federal Flood Insurance Rate Map (FIRM), local floodplain regulations, permits for floodplain development, inspection for compliance, maintaining records of floodplain development, helping residents obtain flood information, floodplain master planning, and storm water maintenance activities. The first FIRM for Boulder was effective on July 11, 1978. Muller Engineering restudied the Boulder Creek floodplain in 1981 in conjunction with local efforts to redevelop Crossroads Mall. MSM Engineering developed the first detailed floodplain study for the tributaries to Boulder Creek in 1983. This new study extended floodway regulations to the tributaries for the first time, causing a great deal of controversy in the community and ultimately resulted in FEMA's issuance of a 3