FAQs • Contra Costa County, CA • CivicEngage

What is the County's responsibility in maintaining private drainage systems?

Contra Costa County has 31 major watersheds and sub-watersheds containing more than 1,300 miles of creeks and drainages. Of that total, the County maintains approximately 75 miles of improved creeks and drainages. The rest is the responsibility of private property owners.

The County maintains only those drainage facilities required as a condition of development constructed to standards applicable at the time of construction and located in an easement or other land right accepted by the County. Creek maintenance is the responsibility of the owner whose property abuts a creek.

When the creek area is not properly maintained, the resulting obstructions can lead to increased flooding, changes in the course of the creek, and increased erosion on the obstructed property and/or downstream properties. See Division 1010 of the Title 10 County Ordinance Code for more information on. The Public Works Department recommends the following guidelines on private creek maintenance (PDF).

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PW - What is, What do I, etc.

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1. What are Area of Benefit (AOB) funds used for?: AOB Funds are used to fund projects that improve the capacity and safety of the existing roadway network. AOB funds will be used to fund projects that are listed on the AOB project list. AOB project lists are available at the Contra Costa County Public Works Department.

2. What are Best Management Practices (BMPs)?: BMPs are devices or control measures for managing stormwater run-off. They include structural drainage inlet protection like catch basin inserts, gravel bags and straw waddles as well as operational controls like training, good housekeeping, adequate spill response and proper material handling and storage.

3. What are Pollutants of Concern (POCs)?: POCs are pollutants that impair waterways which are commonly found in urban run-off. They include Total Suspends Solids (TSS), sediment, bacteria (fecal coliform) and pathogens, heavy metals (e.g., lead, zinc), oil and grease, polyaromatic hydrocarbons (PAHs), synthetic organics (pesticides, PCBs), nutrients (fertilizers), oxygen demanding substances (vegetations, pet waste), and litter.

4. What are the Public Works Counter hours of service, phone numbers, and location?: The Public Works is located at 255 Glacier Drive in Martinez. Office hours are Monday through Thursday from 7:00 a.m. to 5:00 p.m. and Friday from 7:00 a.m. to 4:00 p.m. (closed 12:00 p.m. to 1:00 p.m.). The main phone number is (925) 313-2000.

5. What can property owners do to help the County's maintenance efforts of private trees and other vegetation?: Property owners can help the County’s maintenance efforts by preventing private trees and shrubs from encroaching onto County roads. These encroachments are in violation of Division 1002 of the Title 10 County Ordinance Code. Please see this diagram for acceptable tree clearances (PDF). For information on power lines and trees, please see the PG&E website on this subject.

6. What can property owners do to prevent fallen leaves from creating blockages in the drainage system?: Property owners can help by removing the leaves that have fallen onto their property, and disposing of them in a proper manner. Clear the tops of grates and in front of culvert pipes. With every property owners’ help, we can prevent flooding and help the environment. Please see the Drainage Maintenance Brochure (PDF) for more information on how to prepare.

7. What do I do if my neighbor informed me that I am encroaching on his property?: How did your neighbor come to this determination? Request the official filed map of the survey that provided a surveyor's opinion of your shared boundary line. You can hire a surveyor yourself.

8. What information should I provide when reporting a streetlight outage?: Please provide the following information: the nearest street address, cross street and pole number.

9. What is a cape seal?: A cape seal is applied in a two-step process. The first step in the process involves application of a chip seal; the second step involves the application of a slurry seal. Cape seals are used on collector and residential roads that have a significant amount of wear. Schedule information regarding the contracted cape seal application can be obtained by calling the Public Works Department’s Construction Division at (925) 313-2320.

10. What is a micro-surface seal?: A micro-surface seal is a mixture of fine aggregate and liquid asphalt that is spread over the pavement by a County-hired contractor. Micro-surface seals are used on arterial, collector and residential roads that are in good condition. Schedule information regarding the contracted micro-surface seal application can be obtained by calling the Public Works Department’s Construction Division at (925) 313-2320.

11. What is a slurry seal?: A slurry seal is a mixture of fine aggregate, liquid asphalt and water that is spread over the pavement by a County hired contractor. Slurry seals are used on arterial, collector and residential roads that are in good condition. Schedule information regarding the contracted slurry seal application can be obtained by calling the Public Works Department’s Construction Division at (925) 313-2320.

12. What is a traffic Area of Benefit (AOB)?: A traffic Area of Benefit (AOB) is a development traffic mitigation fee program designed to improve the capacity and safety of the County’s road network within a defined boundary as development occurs. The AOB fee programs are supported by County ordinances which are adopted by the County Board of Supervisors. Money collected within a given AOB will be used to fund road improvement projects that mitigate traffic impacts generated by new development projects.

13. What is a Watershed?: All of the land that drains to a common receiving body of water. In Contra Costa County we have 32 watersheds, several of these share boundaries with Alameda County. Watersheds are commonly named for the waterway or water body they flow to.

14. What is an illicit discharge and who do I call to report it?

An illicit discharge is any non-stormwater discharge or discharge to the storm drain system that is not composed entirely of rain or precipitation run-off.

Call 911 or the Sheriff’s Dispatch (925) 646-2441 to report an illegal discharge going on right now. Call (925) 313-2236 to report an illicit discharge that has taken place in unincorporated County or call 1 (800) NO-DUMPING to report an illicit discharge that occurred in other cities/towns in Contra Costa County.

15. What is an NOI and what permits does it cover?: An NOI is a “Notice of Intent’ application to be included in one of CA’s General Stormwater Discharge Permits. If you are a commercial or industrial facility covered by certain NAIC code like chemical manufacturing or vehicle servicing, you may be required to file an NOI for inclusion in CA’s General Permit for Industrial Facilities. If you disturb soil of more than 1 acre you may be required to file an NOI for inclusion in CA’s General Construction permit. If you are a point source discharger like an industrial facility you may be required to apply for an individual NPDES permit. If you are a municipality that owns/maintains an MS4 you may be required to apply for a Municipal Stormwater Discharge NPDES permit.

16. What is C.3?: C.3 refers to Provision C.3 of the County’s NPDES Permit, which was added to the Permit in 2003. This provision requires stormwater runoff from projects creating and/or redeveloping at least 10,000 square feet of impervious surface to treat stormwater runoff with permanent stormwater management facilities, and requires projects creating and/or redeveloping to design such facilities to control runoff rates and volumes (in addition to treatment). Projects that are not required to comply with C.3 still implement permanent stormwater controls to the maximum extent practicable.

17. What is IPM and what are some ways I can try it?: Integrated Pest Management (IPM) is an ecological approach to dealing with pests using mechanical, physical, biological, and cultural methods first and chemicals generally as a last resort.

18. What is NPDES and who oversees it?: NPDES stands for the National Pollutant Discharge Elimination System. It’s a permitting program required under the U.S. Clean Water Act for discharges to surface waters of the U.S. In CA, USEPA has delegated its authority to implement the NPDES Program to CAL/EPA’s State Water Resources Control Board (SWRCB) who in turn manages the NPDES Program via five Regional Water Quality Control Boards (RWQCBs). In Contra Costa County, two RWCQBs oversee our County’s discharges to the Bay and the Delta, the San Francisco Bay and Central Valley RWCQBs, respectively.

19. What is the Adopt-A-Road Program?: The Adopt-A-Road Program encourages organizations, corporations, groups and individuals to participate by providing volunteers to maintain and enhance Contra Costa County roads. For more information, please refer to our Adopt-A-Road Program guide (PDF). If you have questions about the program, please call (925) 313-7000.

20. What is the construction work occurring on a County Road or Flood Control Facility?: The Department maintains online project information on capital improvement projects. If the project is not on the list, it may be part of a development project and/or is being done under an encroachment permit. Contact the Design/Construction Division at (925) 313-2320.

21. What is the CRIPP?: The CRIPP is a programming document that anticipates revenues and identifies maintenance, rehabilitation, safety, and capacity improvement projects to be funded with the identified revenues.

22. What is the design storm for my project?

The County Title 9 (Title 9: 911-2.010) set the design storm based on the watershed area draining to the creek of drainage facility as follows:

Area < 1.0 sq. mi. Contain, with sufficient freeboard, a ten year frequency of average recurrence interval (10-year)
1.0 sq. mi. ≤ Area ≤ 4 sq. mi. Contain, with sufficient freeboard, a 25-year frequency of average recurrence interval (25-year)
4.0 sq. mi.≥ Area Contain, with sufficient freeboard, a 50-year frequency of average recurrence interval (50-year) OR Contain the 100-year frequency of average recurrence interval (100-year)

23. What is the difference between a Stormwater Pollution Prevention Plan (SWPPP) and a Stormwater Control Plan (SWCP)?: A Stormwater Pollution Prevention Plan (SWPPP) is a document that describes how a project will prevent pollution during the construction process. This document details how erosion will be prevented and how sediment will be controlled, as well as how other construction-related pollutants, such as concrete dust and fluids from construction equipment, will be prevented. SWPPPs, which are required under the California Construction General Permit, must be submitted for projects disturbing at least 1 acre of soil, and for certain projects involving less earthwork but pose special threats to water quality. Smaller projects also are required to implement adequate erosion and sediment controls.

A Stormwater Control Plan (SWCP) is a document that details permanent stormwater management facilities (such as bioretention areas) that will be incorporated into development projects to treat stormwater runoff and control runoff rates and volumes after the construction process is completed. SWCPs are required for projects that must implement permanent stormwater management facilities to comply with C.3 of the NPDES Permit.

24. What is the difference between point source and non-point source?: A point source, also termed ‘end of pipe’ discharge, is a discharge from a defined, discrete conveyance like an outfall coming off an industrial property. The US Clean Water Act was enacted to stop point source discharges like sewage and industrial chemicals to our waterways.

Today, non-point source pollution is the primary contributor of pollutants to our waterways. It comes from a variety of diffuse sources like atmospheric deposition, automotive leaks, and brake pad dust, fertilizer and pesticide use, construction, agriculture, mining and fecal waste. Pollutants from these sources are picked up by urban run-off and deposited into our surface waters impairing their beneficial uses.

Municipalities are required to educate residents and inspect business in stormwater pollution prevention practices.

25. What is the difference between the County Watershed Program and the Contra Costa Clean Water Program?: Both the Contra Costa Clean Water Program and the County Watershed Program (CWP) are tasked with ensuring compliance with the Municipal Stormwater National Pollutant Discharge Elimination System (NPDES) Permit.

The NPDES permit is issued to the Clean Water Program, which is a collaboration between the County (represented by the County Watershed Program), the 19 incorporated cities and towns in the County, and the County Flood Control and Water Conservation District (“Co-Permittees”).

The Clean Water Program (http://www.cccleanwater.org) has its own staff that interacts with regulatory and elected officials, and provides guidance to the Co-Permittees. The Co-Permittees benefit from these collaborative efforts which the individual jurisdictions time and money. Ultimately, however, each jurisdiction is individually responsible for administering the NPDES permit within the bounds of its jurisdiction.

Operationally, the County Watershed Program is a program within the Flood Control Division of the County’s Public Works Department. CWP is responsible for ensuring compliance with the NPDES permit in the unincorporated areas of the County.

26. What is the difference between the storm drain system and the sanitary sewer?: Storm drain systems include the gutter, drainage inlets, catch basins, piping and the waterways they convey stormwater to in order to prevent flooding of our streets. Stormwater flows through these conveyances directly to receiving waterbodies such as the Delta and Bay without being treated. Storm drain systems are also often referred to as MS4s or Municipal Separate Storm Sewer Systems. Sanitary sewers transfer wastewater from our homes and businesses to wastewater treatment plants for primary, secondary or tertiary treatment prior to being discharged to receiving waterbodies via outfall pipes or reclaimed for irrigation purposes.

27. What is the Public Works Budget?: Visit the County Administrator's Office site for the County's budget information including Public Works.

28. What projects are upcoming or currently advertised?: Current and future projects are listed in our Advertised & Upcoming Construction Projects webpage.

29. What should I do if I see someone dumping garbage on private or public property?: Illegal dumping is a serious problem in the County. Do not approach someone illegally dumping on public land or streets. Record the license plate number and vehicle information. When it is safe, contact local law enforcement and report it providing the license plate number and vehicle information (i.e., year, make, model, color, etc.). If the dumping occurs in the unincorporated county report it to the Contra Costa County Sheriff's Department. If the dumping occurs within incorporated city limits report it to the local Police Department. Dumping on private land should be reported to Code Enforcement at (925) 655-2710 for file a complaint online.

30. What is a Chip Seal?

The County Public Works Department Maintenance crews perform two types of chip seal:

A single chip seal involves spraying liquid asphalt on the pavement followed by the spreading of a layer of small aggregate (chips) that is embedded into the oil.
A double-chip seal is a single chip seal with a second application (layer) of liquid asphalt and small aggregate.

Single and double-chip seals are typically used on arterial and collector roads that have a significant amount of wear and high traffic volume. Schedule information regarding the chip seal application can be obtained by calling the Public Works Department Maintenance Division at (925) 313-7000, or you can visit our Pavement Management Program page.

31. What is the basis of the Area of Benefit (AOB) Program?

The Area of Benefit (AOB) Program is based on the following government codes:

California Government Code Section 66000-66025 (Mitigation Fee Act)
California Government Code Section 66484 (Subdivision Map Act)
Title 9 Division 913 of the Contra Costa County Ordinance Code

32. What is the County's responsibility in maintaining private drainage systems?

33. What is the drainage easement across my property? Can I build on it? What can I do on it?

Easements provide the Public Works Department and Flood Control District with land rights for construction, reconstruction, maintaining and accessing its drainage facilities and for other related purposes. Some access easements are not used regularly but must be kept clear for potential future use. An easement allows the property owner use of the property as long as it does not interfere with easement rights.
No permanent structures or encroachments will be permitted or constructed within or over any drainage easement. This includes, but is not limited to: