Calichi Design Group is a civil and stormwater engineering firm with offices in Oakland, CA. We’ve delivered site civil engineering, SWPPP preparation, fire flow analysis, and dry utility consulting for residential, commercial, and institutional projects across the East Bay since 2009. Our proposals are fixed-fee and specific to your site.
Civil Engineering in Walnut Creek, CA
Walnut Creek is the commercial center of central Contra Costa County, and its development pipeline is dominated by dense multifamily and mixed-use work. The Transit Village build-out at Walnut Creek BART is replacing surface parking with hundreds of apartments and ground-floor retail, and the City’s West Downtown planning area between the BART station and Olympic Boulevard is zoned for more of the same. For a Walnut Creek civil engineer, that means constrained infill sites, shared and structured parking, podium drainage, and utility connections threaded through a built-out downtown.
We work with developers, architects, and property owners on Walnut Creek projects from entitlement documents through construction support. Our work here typically involves the City’s Development Engineering division for site development and encroachment permits, one of the city’s two water utilities for service and hydrant capacity, Central San for sewer connections, and the Contra Costa Clean Water Program’s C.3 requirements for stormwater.
Walnut Creek’s terrain also varies more than the downtown core suggests. The flats near the BART station and along the Iron Horse corridor behave very differently from the hillside residential neighborhoods toward the city’s open space areas, and that difference drives grading design, drainage patterns, and infiltration feasibility. We design to the actual site conditions, not regional assumptions.
SWPPP and C.3 Stormwater Design in Walnut Creek
Walnut Creek is a member of the Contra Costa Clean Water Program, which implements the San Francisco Bay Regional Water Quality Control Board’s Municipal Regional Permit for Contra Costa County. Stormwater management obligations for Walnut Creek development projects follow the Program’s Stormwater C.3 Guidebook, currently in its 9th Edition.
Under the current permit, most projects that create or replace 5,000 square feet or more of impervious surface trigger C.3 treatment requirements. Detached single-family homes have a 10,000-square-foot threshold. Projects creating or replacing an acre or more of impervious surface must provide flow control in addition to treatment, sizing facilities so post-project runoff matches pre-project volumes and durations. Separately, any project disturbing an acre or more of soil requires a Stormwater Pollution Prevention Plan under the State’s Construction General Permit.
We prepare the SWPPP and the C.3 Stormwater Control Plan as a coordinated package. Reco Prianto holds active QSD and QSP certifications, so we prepare, certify, and submit the SWPPP without a subcontractor step. For C.3 facilities, we size bioretention cells, flow-through planters, and permeable pavement to the Guidebook’s procedures and integrate them into the grading and drainage design rather than treating them as a late-stage add-on. On podium and structured-parking projects common in downtown Walnut Creek, that usually means flow-through planters and other lined facilities designed for the non-infiltrating case.
Fire Flow Studies for Walnut Creek Projects
Fire protection in Walnut Creek is provided by the Contra Costa County Fire Protection District, the fire authority for the city and much of the surrounding county. New construction, additions, and changes of occupancy that raise the fire suppression demand typically require confirmation that the water distribution system can deliver the required fire flow at adequate residual pressure.
Two water utilities serve Walnut Creek: East Bay Municipal Utility District and Contra Costa Water District. Which one serves your project depends on where the property sits, and their system data, hydrant records, and improvement standards differ. A fire flow study for a Walnut Creek project starts by confirming the serving utility, then models the local distribution network against the fire flow required by the California Fire Code for the building’s occupancy, construction type, and floor area. When available flow falls short, we work through the remediation options with the project team: a main extension, on-site storage and pumping, or a design change that reduces the required flow.
Site Civil, Grading, and the Site Development Permit
Grading and private-site improvements in Walnut Creek run through a Site Development Permit issued by the City’s Development Engineering division. The City requires one for grading, retaining walls over 3 feet in height, alterations to a drainage course, and commercial parking lot work. Work in the public right-of-way, including driveway approaches, frontage improvements, and utility connections, needs an encroachment permit from the same division.
The sequencing matters for schedule: building, site development, and encroachment permit applications can be submitted and reviewed concurrently, but the City issues them in order, encroachment permit first where one is required, then the Site Development Permit, then building permits. We prepare the civil documents for all three tracks and respond directly to the City’s plan check comments, which keeps the response cycle tight. See our grading plan services page for how we structure the grading package itself.
Dry utility coordination in Walnut Creek means managing service installations and relocations with PG&E, AT&T, Comcast, and other franchise utilities, and on downtown infill sites the joint trench often has to fit between existing services in a congested frontage. We start that process early so the underground utility design doesn’t conflict with grading or paving schedules.
Walnut Creek Agencies and Jurisdictions We Coordinate With
City of Walnut Creek
The City’s Development Engineering division, part of Public Works Engineering Services, reviews subdivision maps and lot line adjustments, issues Site Development Permits for grading and other private-site improvements, and issues encroachment permits for work in the public right-of-way. Plan review starts with a plan check deposit and ends with a comment letter or a permit-ready letter. We prepare the submittal packages and carry them through plan check to issuance.
East Bay Municipal Utility District and Contra Costa Water District
Walnut Creek is one of the Bay Area cities served by two separate water utilities, EBMUD and CCWD, each with its own service territory, standards, and development services process. New water services, fire services, hydrants, and main extensions go through whichever utility serves the parcel. We confirm the serving utility at project startup and prepare water improvement plans to that utility’s published standards.
Central Contra Costa Sanitary District (Central San)
Central San provides sanitary sewer service to Walnut Creek and much of central Contra Costa County. New sewer connections, lateral replacements, and main extensions follow Central San’s design standards and permit process, and capacity fees are assessed at connection. We design the on-site sewer system, prepare the connection documents, and coordinate plan review with Central San’s development services staff.
Contra Costa County Fire Protection District
The Contra Costa County Fire Protection District is the authority having jurisdiction for fire code compliance in Walnut Creek, including fire apparatus access, hydrant spacing, and fire flow. We design fire access roads and turnarounds to the District’s requirements and coordinate fire flow study submittals with the District and the serving water utility.
Contra Costa Clean Water Program
The Program administers post-construction stormwater requirements for Contra Costa County’s municipalities under the Regional Water Quality Control Board’s Municipal Regional Permit. Its Stormwater C.3 Guidebook governs facility selection, sizing, and operations and maintenance requirements. We use the current edition as the design standard on every Walnut Creek project that triggers C.3 requirements.
Projects Near Walnut Creek, CA
We reference only confirmed projects from our portfolio. The following East Bay projects reflect the project types and regulatory environment we navigate regularly in Walnut Creek:
- Dublin Transit Center (Dublin, CA): New construction of a 516-space, 5-story parking structure on a 2.5-acre site. BART-adjacent structured parking on a tight urban parcel is directly comparable to the parking replacement and podium work in downtown Walnut Creek’s Transit Village area.
- 57-Unit Affordable Housing Complex (Oakland, CA): Civil entitlement documents and full construction documents for a 57-unit mixed-use affordable housing project at 95th and International Boulevard, including City of Oakland and Caltrans encroachment permits. Dense multifamily infill of exactly the kind Walnut Creek’s downtown plan calls for.
- Fremont High School Net-Zero Campus (Oakland, CA): Civil, grading, drainage, and stormwater design for a nine-building, 190,000 square foot campus replacement for Oakland Unified School District, reviewed by the Division of the State Architect.
- Chase Bank West Coast Expansion Program: Engineer of Record for civil engineering, stormwater design, and permitting on over 100 retail banking locations across California, Nevada, and Arizona, including multiple Bay Area sites with C.3 obligations and ADA upgrade requirements.
We’ve also published Walnut Creek planning guidance drawn from this work: see multifamily site planning in Walnut Creek, retail and mixed-use site planning in Walnut Creek, and fire flow analysis in Walnut Creek.
Frequently Asked Questions: Civil Engineering in Walnut Creek
When does a Walnut Creek project need a Site Development Permit?
The City of Walnut Creek requires a Site Development Permit for grading, retaining walls over 3 feet in height, alterations to a drainage course, and commercial parking lot improvements. The application runs through the City’s Development Engineering division with a plan check deposit, and the permit is issued after any required encroachment permit and before building permits. We scope the required permits at project startup so nothing surfaces late in plan check.
What triggers C.3 stormwater requirements in Walnut Creek?
Under the Contra Costa Clean Water Program’s current requirements, most projects creating or replacing 5,000 square feet or more of impervious surface must provide C.3 stormwater treatment. Detached single-family homes trigger at 10,000 square feet. Projects creating or replacing an acre or more of impervious surface must also provide flow control. The governing procedures are in the Program’s Stormwater C.3 Guidebook, and we apply the current edition on every qualifying Walnut Creek project.
Who reviews water and fire for Walnut Creek projects?
Water service comes from either EBMUD or Contra Costa Water District depending on where the property sits, and new services, hydrants, and main extensions go through the serving utility’s development process. Fire code compliance, fire access, and fire flow are reviewed by the Contra Costa County Fire Protection District. We coordinate with both, and the fire flow study ties the two together: the District sets the required flow and the utility’s system has to deliver it.
Does Calichi handle the full civil package for Walnut Creek projects or just specific studies?
We do both. Some clients hire us for a standalone scope, typically a fire flow study, SWPPP, or grading plan. Others retain us for the full civil engineering package from entitlements through construction. We’re structured for both and we’re clear about scope in the proposal so there’s no ambiguity about what’s covered. For projects in Walnut Creek and the surrounding East Bay, contact us with the address and scope and we’ll return a fixed-fee proposal within five business days.
Start a Walnut Creek Civil Engineering Project
If you’re planning a multifamily, commercial, or institutional project in Walnut Creek, we want to hear about it. Share the address and scope and we’ll return a fixed-fee civil engineering proposal within five business days. No open-ended hourly billing. No proposal fee. Contact Calichi Design Group to get started.