Storm Drainage Master Plan

Storm Drainage Master Plan

In 2011 the City of Elk Grove (City) adopted a comprehensive Storm Drainage Master Plan (SDMP) to provide a variety of drainage concepts for upgrading the existing storm drainage and flood control collection (SD &FCC) system. The SDMP identified and analyzed drainage deficiencies throughout the city and provided a range of drainage concepts for the construction of future facilities required to serve the city at buildout of the General Plan and established criteria for selecting and prioritizing projects. Furthermore, the SDMP may be utilized for the development of a capital drainage financing program. The SDMP combined the demands of flood-risk reduction with ecosystem enhancements while incorporating urban development and rural residential land uses to provide an effective plan that meets both the City's and community's vision.

The successful development of the SDMP included active participation and involvement of a diverse set of key stakeholders, including the public, City staff, outside experts and an Expert Advisory Committee (EAC). The City conducted many workshops in various areas of the city to solicit input to obtain a robust perspective of stakeholder concerns and priorities for the SDMP. The overall objective of the SDMP was to develop an up-to-date document with specific key concepts, identify new programs while recognizing and improving existing programs, and identify preliminary candidate watershed projects to satisfy current local interests, accommodate changing trends, philosophies, regulations, and standards, ensure maximum effectiveness and cost efficiency, and meet evolving community goals and objectives that address flood control while promoting a healthy and vibrant ecosystem.

A minor update was completed in 2019, which provides a summary of projects completed since adoption of the 2011 SDMP.

The SDMP is organized into two volumes and an Environmental Impact Report (EIR) as follows:

Volume I

Volume I describes the development of this SDMP; guiding principles; regulatory framework; background and key concepts; existing and proposed program activities; candidate watershed projects; and partnerships, funding, and implementation of the SDMP.

Volume I Minor Update (2019)

In 2019, the City prepared a minor update to the SDMP. The purpose of the minor update is to provide a summary of projects completed since 2011, provide details regarding remaining projects, including implementation costs and schedules (if available) and provide information regarding new regulatory requirements related to stormwater management and flood control. Volume II was not updated as part of the minor update.

Volume II

Volume II supports the technical components of the Plan and is categorized by the city's thirteen major watersheds. Included in Volume II is a description of the planning criteria used to evaluate the storm drainage systems, evaluation of the performance level of the existing SD &FCC facilities and identification of performance deficiencies, identification of potential impacts of future development on existing major facilities, and identification of existing and new facilities upgrades to serve buildout conditions of the City's General Plan.

The EIR evaluates the broad environmental effects of future improvements and new development to comply with California Environmental Quality Act (Section 21000, et. seq. of the California Public Resources Code, hereafter CEQA) addressing program EIRs.

Project Location

The SDMP study area is located throughout the city, within southern Sacramento County. Storm drainage within the city is conveyed through a SD &FCC system consisting of approximately 400 miles of underground pipes and 60 miles of natural and constructed channels. The SDMP encompasses programs and project locations throughout both urbanized and rural areas within the city. The terrain throughout the city is relatively flat, with natural creeks and channels that traverse the city. The eastern portion of the city (primarily east of Waterman Road) is predominantly rural with residences built on large lots and where agricultural uses are common.

While the SDMP encompasses program and project locations throughout the city, it has been further categorized into four separate regions, as listed below. These four regions have unique and different land use characteristics; therefore, SD&FCC deficiencies and new development are evaluated and addressed differently:

  • Elk Grove Creek Region:Southeast portion of the city, beginning just east of Grant Line Road and joining Laguna Creek just west of State Route 99;
  • Shed C Region:Southernmost portion of the city, beginning on the west side of State Route 99 and continuing southwest outside the city limits to the Stone Lakes National Wildlife Refuge located west of Interstate 5;
  • East Elk Grove Area/Rural Region:Bounded by Waterman Road on the west, Calvine Road on the north, and Grant Line Road/city boundary on the east; this area includes Grant Line Channel, Deer Creek, and Laguna Creek; and
  • Other Urbanized Areas:Includes well-developed areas in the city that are builtout with residential, commercial or industrial land uses.

The city's stormwater runoff drains within thirteen (13) watersheds. Within the watersheds there are ten (10) major natural creeks or open channels that convey stormwater runoff within the city including Elk Grove Creek, Laguna Creek, Strawberry Creek, Whitehouse Creek, Deer Creek, Shed A Channel, Shed B Channel, Shed C Channel, Grant Line Channel, and Laguna West Channel. Four (4) of the creeks convey runoff that originates outside of the city limits: Deer Creek, Elk Grove Creek, Laguna Creek, and Strawberry Creek. All of the city watersheds ultimately drain into the Stone Lakes National Wildlife Refuge area of Sacramento County, with the exception of the Deer Creek and Grant Line Channel watersheds, which drain to Deer Creek and ultimately to the Cosumnes and Mokulmne Rivers.


The SDMP was developed from a general perspective with goals, objectives and key concepts to a more detailed program and candidate watershed project basis. The SDMP integrates multiple objectives to address deficiencies and improvements to the city's SD&FCC system while addressing water quality, aquatic resources, and habitat enhancement and protection. The SDMP components consist of: 1) Guiding Principles developed to set a foundation and help guide the processing of the SDMP; 2) existing and proposed programs; and 3) a multitude of preliminary candidate watershed projects designed to achieve one or more of the six candidate watershed project objectives as follows:

  • Flood Protection:Protection, restoration, and enhancement of the flood control facilities and waterways to convey floodwaters and provide flood control services for the city.
  • Drainage Deficiencies:Protection, restoration, and enhancement to the drainage conveyance system to convey water and provide stormwater facilities for the city.
  • Water Quality:Protection, restoration, and enhancement of water quality to protect and maintain important beneficial uses upon which the community, plants, and habitat rely upon.
  • Habitat:Protection, restoration, and enhancement of vegetation communities and aquatic resources, which provide habitat for numerous plant, wildlife, and fish species.
  • Education and Stewardship:Development, implementation, and promotion of important education, interpretation, and stewardship opportunities throughout the city for the enjoyment and enrichment of the public.
  • Recreation:Protection, restoration, enhancement, and creation of important recreational amenities for the public to enjoy.

Environmental Analysis

The City has prepared an EIR to address the specific environmental effects of implementing the SDMP. The EIR consists of a focused analysis of the following environmental issue areas that may be impacted by the project:

  • Aesthetics
  • Air Quality
  • Biological Resources
  • Air Quality
  • Greenhouse Gas Emissions and Climate Change
  • Hazardous Materials
  • Hydrology and Water Quality
  • Recreation
  • Cumulative Impacts
  • Long Term Implications

Fiscal Impact

The SDMP is a programmatic-level document that is not intended to provide specific details on drainage projects, including their estimated costs. The financial impact to the City, however, will be determined as projects and programs are selected, prioritized and approved. The following three funding sources are currently available for implementing the projects and programs within the SDMP:

  • Stormwater Utility Fee (Drainage Fund);
  • Sacramento County Zone 11A Fee (Drainage Impact Fee Program); and
  • Grants.

Stormwater Utility Fee (Drainage Fund):

Each year, the drainage fund budget is appropriated to provide operation and maintenance, stormwater quality, replacement costs of the existing SD &FCC, and construction of new SD &FCC. The City's Capital Improvement Plan (CIP) spans five years and is updated annually to reflect the most current cost estimates and needs. This long-term approach provides an extended outlook, and allows for phasing of infrastructure based on available funding. The CIP process also allows for comprehensive planning and prioritization of infrastructure improvements City-wide.

Sacramento County Zone 11A Fee (Drainage Impact Fee Program):

Currently, the Zone 11A drainage impact fee program reimburses developers (under agreement with the County of Sacramento) for the oversizing of trunk drainage facilities within the city based on established criteria. Unfortunately, the Zone 11A program generally does not reimburse the developer completely. To help offset this shortfall, a supplemental drainage fee impact program(s) may be established to reimburse future development projects for backbone SD &FCC facilities constructed within the city. Establishment of such a program(s) will involve all applicable stakeholders and will require a nexus study to be generated to ensure that the benefit and costs of the facilities are spread equitably. Any fee program established by the City will require City Council review and approval.


The SDMP will greatly position the City to be more prepared and eligible for grant opportunities on projects and programs related to flood control, stormwater quality, habitat protection, watershed restoration, open space recreation, etc. Grant awards will help offset and reduce the dependency on other funding sources, i.e. impact fees and the annual drainage budget to implement the projects and programs within the SDMP.


The programs, candidate watershed projects and future development proposals associated with the City's SD &FCC system will be evaluated for consistency with the SDMP. Each program or project will be identified and evaluated on a project level, including the environmental component. Each specific candidate watershed project will be analyzed to provide alternatives which can incorporate various key concepts to help select a preferred solution. Specifically, alternatives for each project will be examined to improve drainage conveyance, flood control, water quality, aquatic resources and habitat enhancement and protection, wherever and whenever feasible.

This SDMP presents key information that will help Elected Officials, City staff, stakeholders, property owners, and land developers make recommendations and decisions for existing and future SD &FCC facilities, while meeting ecological needs and compliance with regulatory requirements. This Plan reflects the best information available during the drafting of the document, however, it is understood that over time new information will become available and modifications will be necessary to keep this Plan "living" and current. Therefore, updates to the SDMP will be required from time to time.