Flooding in the City of Roseville is largely associated with stormwater runoff exceeding creek and storm drainage capacities, both in the city and surrounding communities. Areas adjacent to the creeks are subject to both flash flooding and riverine flooding. Since 1992, Roseville, California has been active in the Community Rating System to reduce flooding risks. Roseville is the first and only community in the nation to receive CRS’s highest rating of a Class 1 community.
Roseville has maintained their Class 1 CRS rating by adopting all of FEMA’s recommended activities. Only 7% of the city is located within a floodplain, but the city has taken action to prevent losses. The city voluntarily bought-out 273 homes at high risk of flooding to convert the majority of the floodplain to open space. Current development requirements include the prohibition of construction or infilling within the 100-year floodplain, except in the center of the city and only if no adverse impact is demonstrated. The floor elevation of any structure is required to be above the future 100-year floodplain water surface elevation. Ongoing flood control projects include the operation of an alert system that predicts and broadcasts flood warnings and an annual streambed maintenance program. Regional flood control efforts are coordinated through the Placer County Flood Control District which operates detention basins and collects developer-paid fees to pay for improvements. Specific past projects include:
- Elevating flood-prone homes
- Quadrupling the size of a culvert on Linda Creek to handle a 100-year storm
- Adding, enlarging, and improving culverts along Linda Creek
- Replacing a bridge to widen Cirby Creek’s channel for larger stream capacity
- Removing culverts from under railroads (the Union Pacific Culvert Removal Project)
- Acquiring homes in the floodplain (the Linda Creek and Cirby Creek/I-80 projects)
Implementation & Funding
The City of Roseville funded most of these projects at a cost of about $14.9 million over almost 30 years. Today, annual maintenance and upkeep costs are around $350,000. FEMA funded 75% ($750,000) of the Home Elevation Program and $8.7 million of flood control improvements on Linda Creek. Union Pacific Railroad Company funded almost all of the culverts removed from under railroads at a cost of $2 million.
Because of the great Class 1 CRS rating, residents within the 100-year floodplain can receive 45% discount on their flood insurance premiums, while those outside the floodplain can receive 10% insurance premium discounts.