Press Enter to show all options, press Tab go to next option


Storm Water & Water Pollution Control Facilities
The City of Belmont’s storm water program can essentially be divided into three components: maintenance and operation of storm drainage infrastructure, storm water pollution prevention and Permit compliance, and street sweeping. The 1972 Clean Water Act established the National Pollutant Discharge Elimination System (NPDES) permit program to regulate the discharge of point source pollution into US waters. Until 1987, non-point source pollution from storm water runoff was largely unregulated. However, the 1987 amendments to the Clean Water Act extended the NPDES permit program to storm water runoff, effectively prohibiting non-storm water discharges to municipal separate storm sewer systems, and implementing controls to reduce storm water pollution to the maximum extent practicable.
Stormwater Permit Requirements
The NPDES Permit requires jurisdictions to implement programs and activities to reduces pollutants in storm water and urban runoff. Since the program was established in 1987, storm water regulations under the NPDES permit program have been significantly revised and expanded without any dedicated funding sources. The funding sources for the operations and maintenance of the City's drainage system, and compliance with the Federal and State water quality standards and mandates are primarily from NPDES storm drainage fees (which has not been adjusted since 1996, due to Proposition 218 provisions), sewer fees as it relates to reduction of storm water inflow and infiltration into our sewer system,  and street sweeping through trash fees. The City has no dedicated funding source for storm drainage capital improvement projects. 
Stormwater Conveyance (4 Belmont drainage areas)

The City has a total area of 4.6 square miles and four main drainage areas that convey storm water through the City:

  1. The primary storm drainage conveyance through the City is Belmont Creek which conveys 60% of the City’s storm runoff.
  2. Laurel Creek has a 0.78 square mile drainage area in the northwestern portion of the City and discharges to the City of San Mateo.
  3. O’Neill Slough is located east of Highway 101 and is hydraulically connected to San Francisco Bay.
  4. Island Park is east of the Highway 101 which drains to a lagoon that connects to Belmont Creek.
Belmont's Stormwater Infrastructure

The City’s storm infrastructure consist of 28 miles of storm drain pipes and two storm pump stations.  There are a number of areas in the City that do not have any storm drain pipes.  The existing 28 miles of storm lines are made up of:

  1. Corrugated Metal Pipe (CMP) [11,300 feet citywide, 2.1 miles]
  2. Reinforced Concrete Pipe (RCP) [132,800 feet citywide, 14.3 miles]
  3. High-Density Polyethylene Pipe (HDPE) and Polyvinyl Chloride Pipe (PVC) [61,526 feet citywide, 11.6 miles] 
Storm Drainage Study

In 2009 the City completed a Storm drainage study which documented the existing City storm drainage system and  identified drainage deficiencies.  More detailed information can be found in the June 26, 2007 staff report.

The estimated cost to correct the deficiencies were estimated at $44 million.  These costs were updated in late 2013 to an estimated $55.6 million as follows:  

  1. Repair and replacement of deficient pipe ($29.3million)
  2. Installation of new storm pipes, where currently none exist, to help with storm and flooding issues ($20.2 million)
  3. Installation of Curb & Gutter Improvements ( $3.3 million)
  4. Improvements to Belmont Creek to convey a 100-year flood event ($2.8 million)

The storm water forecast increases the City’s infrastructure backlog. Addressing infrastructure issues is one of the City’s highest priorities, but also presents a significant challenge given tight budgetary constraints and valid competing priorities.

Report of NPDES Charges


City of Belmont National Pollutant Discharge Elimination System

Report of Charges 2019-2020