Stormwater Performance Charts
Monthly Target amounts are a good indicator of production but can vary during the holiday season, inclement weather conditions and employee vacancies. Monthly data is also impacted by downtime equipment failures, temporary departmental priority shifts and short term supplemental contract services. The Year to Date average (YTD) provides a better indication of measuring production against established performance measures.
There are 49 active capital projects that are in the planning and development, design or construction phase. The number of projects varies each year according to approved funding levels. Stormwater projects are designed and built to enhance public safety by reducing property damage and roadway flooding.
Stormwater cave-ins occur regularly throughout the City and are typically more prevalent in the wetter months. A cave-in is a depression in the right-of-way that is caused by a failing utility. Each utility department (Water, Wastewater, and Stormwater) encounters cave-ins and repairs them according to severity and urgency. On an average, Stormwater Operations repairs 150 to 175 cave-ins per year which equates to 2 to 4 cave-ins per week. All stormwater cave-ins are repaired by City in-house resources.
The City has many headwalls throughout the right-of-way. A headwall is constructed of brick, concrete, or rip rap bags, and is built at the outlet of a drainpipe or culvert with the end of the pipe flush with the outer surface of the wall. Services include inspection and as-needed maintenance.
There are approximately 188 miles of stormwater ditch systems within the City. The performance target for inspection and maintenance is 26.9 miles per year (2.4 miles per month). Debris, sediment, and vegetation are removed and transported to a facility for processing. Ditches that need maintenance are graded by in-house resources and contractors. Ditches are cleaned, graded and sodded to reduce flooding and enhance water quality.
There are 26,857 Inlet structures within the City. The performance target for inspection and cleaning is 3,840 per year (320 per month). Debris, sediment, and vegetation are removed and transported to a facility for processing. Additionally, the structure type, size, location and its condition are documented to determine necessary repair and restoration projects. This work is conducted primarily by in-house resources and is done to reduce flooding and enhance water quality.
Included in the infrastructure totals for inlet structures are the City’s baffle boxes. Baffle boxes are concrete structures containing a series of sediment settling chambers separated by baffles. The primary function of baffle boxes is to remove sediment, suspended particles, and associated pollutants from stormwater. Baffle boxes can also capture larger materials, trash, and floatables. The City’s baffle boxes are maintained by a contract on a quarterly basis.
An outfall is a point where collected and concentrated surface and stormwater runoff is discharged from a pipe system or culvert. The City has an inventory of over 900 outfalls with approximately 378 of those listed as “major.” A Major outfall is defined by the NPDES MS4 permit as a 36” in diameter or larger pipe, or an outfall that drains an area larger the 50 acres. The maintenance goal for outfalls is to inspect all of the major outfalls every year. Outfalls that need maintenance are cleaned by in-house resources and contractors.
There are approximately 575 miles of stormwater piping within the City. The performance target for inspection and cleaning is 75 miles per year (6.25 miles per month). Debris, sediment, and vegetation are removed and transported to a processing facility. Additionally, the culvert type, size, location and its condition are documented. This work is done to reduce flooding and identify necessary repair and restoration projects.
The City currently maintains 144 ponds, 85 miles of ditches and 27 vacant lots reserved for future ponds. To keep storm water ponds and ditches functioning properly they require monthly maintenance. The maintenance includes grass-cutting, pond spraying of invasive vegetation, Fence repairs, sediment dredging, removal of illegal dumping and trash pickup. Storm water ponds and ditches are designed to collect rainwater from impermeable surfaces such as parking lots, roads and buildings. Rainwater is absorbed into the soil helping prevent flooding and improve the water quality in the aquafer, river and bay. Maintenance is a key part needed to help keep the city above water.
Street sweeping services are delivered every two months for residential and business areas with curb and gutter type streets. Additionally, the City’s growing number of special events, parades, and runs, add a significant amount of streets each year that require sweeping. The performance target for the residential street sweeping program is a 60-day cycle and is tied to annual funding levels. Seven street sweepers are used to remove debris, sediment, and vegetation to prevent discharge into the City’s waterways. Last year over 5,700 tons of pollutants were removed and transported to a facility for processing. Street sweeping is done to keep streets and stormwater systems clean, reduce flooding and enhance water quality. You can access the street sweeping routes on the City’s web page to determine when sweeping will occur in your area.