Stormwater & Erosion Control
Erosion & Sediment Control Plans
Site-specific erosion and sediment control sheets drawn to your agency's checklist, so plan reviewers, contractors and inspectors work from one plan.
What is an erosion control plan?
An erosion and sediment control plan is a set of drawings and notes showing where and when best management practices (BMPs) will keep soil in place and out of storm drains and waterways during construction.
Often shortened to erosion control plan, ESC plan or ESCP, it usually sits in the grading plan set. The city or county reviews it before issuing a grading or building permit, and inspectors check the site against it. Some agencies call the rainy-season version a winter or wet weather erosion control plan.
It is not the same document as a SWPPP. Sites disturbing one acre or more also need a Stormwater Pollution Prevention Plan (SWPPP), whose drawings show the same BMPs, so the two work best prepared together.
Deliverables
What's included in an erosion control plan
Scope follows your agency's checklist and is set in the proposal. A typical plan covers:
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BMP site plan
Plan-view sheets locating every erosion, sediment and tracking control on the grading base.
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Erosion controls
Mulch, hydroseeding, blankets and preserved vegetation that keep disturbed soil in place.
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Sediment controls
Silt fence, fiber rolls, inlet protection, and sediment basins or traps where needed.
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Entrances & wind control
Stabilized construction entrances and exits, plus dust and wind erosion measures.
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Drainage & run-on
Diversions, slope drains, check dams and outlet protection that move water without erosion.
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Phasing & seasons
Controls shown for each construction phase and for wet- and dry-season conditions.
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Details & notes
Standard BMP details, installation and maintenance notes, and the site's erosion control contact.
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Supporting calculations
Sediment basin and temporary drainage sizing, plus soil-loss estimates when the agency asks.
When do you need an erosion control plan?
Plan for one whenever a permit involves disturbing soil; your city or county sets the format.
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Grading permit applications
Most agencies approve the plan before issuing a grading permit. See grading plans.
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Sites disturbing one acre or more
The erosion and sediment control drawings feed the SWPPP the Construction General Permit requires.
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Small sites under one acre
Local ordinances and California's green building code (CALGreen) still require runoff controls on smaller builds.
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Grading into the rainy season
Agencies check sediment controls before wet-season grading; some require a winter plan or approval.
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Slopes, creeks and sensitive areas
On Construction General Permit sites, steeper slopes may need closer sediment barriers, and creeks within 50 feet a buffer or equivalent controls.
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Subdivisions, streets and utilities
Phased plans cover mass grading, street and utility work, and final stabilization. See improvement plans.
Process
How an erosion control plan is prepared
Five steps from agency checklist to buildable sheets.
Confirm agency requirements
We confirm your agency's plan format, preparer qualifications, standard notes and wet-season dates, and whether a SWPPP can stand in for the plan.
Assess the site
Working from the topographic survey and grading design, we map drainage areas, run-on, slopes, soils, discharge points and nearby waterways.
Select and place BMPs
Erosion, perimeter, inlet, entrance and wind controls are placed for each construction phase and season.
Size basins and drainage
Where needed, sediment basins and temporary diversions are sized from hydrology calculations, with soil-loss estimates backing the BMP choices.
Detail, submit and revise
Sheets carry BMP details, maintenance notes and a schedule. We answer plan-check comments, revise the plan as phasing changes, and support field SWPPP inspections.
California rules
California requirements for erosion control plans
State permits set minimum controls; your city or county sets the plan format.
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Small MS4 Permit §E.10.b
Cities and counties require the plan
Cities and counties under the Small MS4 (municipal separate storm sewer system) permit must require an erosion and sediment control plan before issuing a grading or building permit, with site-specific BMPs, the rationale for them and a list of related permits. A project's SWPPP may substitute, though the agency still reviews it against its own ordinance.
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Order WQ 2022-0057-DWQ §II.A, §III.A, §IV.O
One acre or more: the SWPPP carries the drawings
Sites disturbing one acre or more, or part of a larger common plan that will, need Construction General Permit coverage before work starts. The SWPPP, written by a Qualified SWPPP Developer, shows the proposed erosion and sediment control BMPs on its drawings.
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CGP Attachment D §II.D–II.E
Minimum erosion and sediment controls
Permitted sites must limit exposed soil, keep erosion control materials on site or nearby year-round, maintain perimeter controls and stabilized entrances, and immediately begin stabilizing any area where earthwork has stopped for good or won't resume for more than 14 calendar days. Sediment basins follow the California Stormwater Quality Association design method.
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CALGreen §4.106.2
New homes under one acre
CALGreen, Part 11 of the 2025 California Building Standards Code, requires new homes and additions disturbing under one acre, and not part of a larger common plan of one acre or more, to retain construction runoff on site, filter it through a barrier or wattles, or follow a local stormwater ordinance.
Requirements vary by city and county; the Construction General Permit does not override local stormwater authority. Santa Cruz County, for example, requires a separate Winter Grading Approval and a full erosion control plan for grading between October 15 and April 15.
Sources & references
- Phase II Small MS4 General Permit, Order WQ 2013-0001-DWQ (conformed), Section E.10 (State Water Resources Control Board)
- Construction Stormwater General Permit, Order WQ 2022-0057-DWQ (State Water Resources Control Board)
- Attachment D: Traditional Construction Risk Level Requirements, Order WQ 2022-0057-DWQ (State Water Resources Control Board)
- 2025 California Green Building Standards Code (CALGreen), Chapter 4, §4.106.2 (ICC Digital Codes, free public viewer)
- Winter Grading Approval (County of Santa Cruz)
Last reviewed .
Erosion control plan FAQs
What does an erosion and sediment control plan show?
An erosion and sediment control plan shows the limits of disturbance, drainage patterns, discharge points, stockpile and staging areas, and every erosion, sediment and tracking control. Standard BMP details, installation and maintenance notes, and the construction phase each measure serves complete the sheets.
What is the difference between an erosion control plan and a SWPPP?
An erosion and sediment control plan is a set of plan sheets a city or county reviews with a grading or building permit. A SWPPP (Stormwater Pollution Prevention Plan) is the document the Construction General Permit requires for sites disturbing one acre or more, prepared by a Qualified SWPPP Developer. Where the Small MS4 (municipal storm sewer) permit applies, the SWPPP may substitute for the local plan, and the agency reviews it against its own ordinance.
Do I need an erosion control plan if my project disturbs less than one acre?
A project disturbing less than one acre usually falls outside the Construction General Permit, but local rules still apply. Cities and counties under the Small MS4 (municipal storm sewer) permit must enforce a construction runoff ordinance for these sites, and California's green building code (CALGreen) §4.106.2 requires new residential construction under one acre to manage construction runoff. Formats range from a full plan sheet to a standard notes form.
Who can prepare an erosion control plan in California?
The preparer of an erosion and sediment control plan is set by the local agency; no single statewide rule applies. For sites of one acre or more, a Qualified SWPPP Developer (QSD) prepares the SWPPP and its drawings. California-licensed civil engineers, professional geologists and engineering geologists may self-register as QSDs through the State Water Board's SMARTS system; other applicants complete the California Stormwater Quality Association (CASQA) course and exam after a prerequisite credential such as Certified Professional in Erosion and Sediment Control (CPESC).
Can you grade during the rainy season in California?
Rainy-season grading in California is regulated by each city or county; there is no statewide grading moratorium. Agencies often require an approved or updated erosion control plan before work continues into the wet season, and some require a separate winter grading approval.
What affects the cost and schedule of an erosion and sediment control plan?
The cost and schedule of an erosion and sediment control plan depend on the disturbed area, slopes and soils, the number of construction phases, wet-season work, any sediment basin or drainage calculations, and the agency's plan-check requirements. Share the grading or site plan, the address and planned construction dates; the proposal then sets scope and timing.
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