The storm drainage system for Rancho Murieta is comprised of natural swales, pipelines and flood control levees. The key principles that guide the system are:
- To protect life and property and minimize inconvenience to the public,
- To create a realistic balance between inconvenience and protection against a hazard,
- To provide adequate measures to protect the natural resources within the community and
- To protect the community's drinking water supplies from urban runoff contamination.
In the past, storm drainage and flood control jurisdiction had been the overlapping responsibility of property owners and homeowners associations, Sacramento County and the District. In the mid 1980's, the District's latent authority to provide drainage and flood control services was exercised. The District de-annexed from the County storm drainage maintenance district and began providing drainage services to the community.
Significant storm drainage facilities within a community include natural drainage courses which convey seasonal run-off, 100 year flood protection levees along the Cosumnes River, perennial storm drainage detention basins and marsh and wetland areas. In addition small to large diameter pipelines and pump stations convey runoff to the ditches and river.
The level of protection provided by the storm drainage system is:
- Protection of developable areas from the 100 -year flood event.
- Street drainage systems are designed for the 10-year storm.
- Culverts, open channels and natural streams are designed for the 100-year storm.
- Finished floor elevation should be a minimum of 1 foot above the 100-year storm water surface.
Maintenance of this system includes those factors that are essential to keep the drainage system in good condition, maintaining an adequate staff to accomplish the work and instituting practices and procedures for maintenance of existing and future structures and facilities.
The annual maintenance program includes periodic maintenance by mechanical equipment of the natural drainage courses and ditches, cleaning of silt, branches, weeds and other debris from ditches, natural courses and pipelines. In addition, the District provides periodic inspections of the levees and weekly monitoring and maintenance of drainage pumping facilities.
Many times, the District is called out for drainage problems outside their responsibility. The division of responsibility between the District and private property owners, whether individuals or homeowners associations, is as follows:
- The District is responsible for maintenance of the bottoms of natural drainage courses, ditches and canals as well as underground pipe systems and detention basins.
- Individual property owners or the homeowners associations are responsible for maintenance of the open space above the ditch bottom and debris removal in the streets and gutters.