The city of Round Rock is moving forward with a plan with the Upper Brushy Creek Water Control & Improvement District toward reducing the amount of housing structures within a 100-year flood plain. According to city documents, more than 60 homes in southwest Round Rock and some roadways crossing Lake Creek are located in a 100-year, or 1 percent, flood plain. The 100-year flood plain is the area that will flood during a major storm that has a 1 percent chance of occurring in any given year. Furthermore, many of these homes and roadways are also within a 10 percent, or 10-year, flood plain, according to city documents. To reduce the amount of structures within the flood plain, the city and district are contemplating building an earthen dam within the watershed of Lake Creek, upstream from the homes in the 100-year flood plain. The dam, an engineered structure made of earth, clay and other resistant materials, would be a component of a larger plan by the district to improve the drainage issues. Ruth Haberman, Upper Brushy Creek WCID general manager, said the project is very preliminary and the dam site or the entire plan could change at a later date. The dam, in theory, would release water at a slower rate during such a flood, therefore reducing the number of homes in the flood plain. Round Rock Utilities Director Michael Thane said this is the most important drainage issue in the city. "This is No. 1, and No. 2 is about 10 steps back," Thane said. Thane said 80 percent of the flooding issues in the city could be improved with this project. Residents with mortgages from federally regulated or insured lenders in high-risk flood areas are required to have flood insurance. Thane said at one point the city looked at simply purchasing the homes, but the cost of doing so was ultimately more expensive. Thane said the city puts a preliminary estimate for the dam at about $16 million to $20 million. He said the city believes it has the capacity to fund approximately half of the project. Upper Brushy Creek WCID has committed to about a quarter of the funding. The city has reached out to Williamson County for the last quarter of the funding. However, Robert Daigh, senior director of infrastructure for Williamson County, said the county does not have dollars allocated for the project. "It's unquestionably a great project," Daigh said. "But it was brought to our attention after the bond package was put together." However, Daigh said the county will look for money to put toward the project. Thane said the city is also looking for grant money and other revenue sources. The WCID is also leading the design and constructioderway.