Blythe — Overlay Districts

Last reviewed: July 1, 2026

Overview

Blythe’s zoning code (Title 17) recognizes several overlay districts that modify or layer on top of the base zoning shown on the Official Zoning Map. The overlays documented in the code today are the D-O redevelopment/design-focused overlay, the HEO Housing Element Overlay, and the C-M-O Commercial Manufacturing Overlay. Each overlay changes how uses are approved or reviewed, while dimensional standards generally come from the underlying zone unless the overlay says otherwise. The list of zones (including overlays) is codified in §17.06.010; the Official Zoning Map is adopted by §17.06.020.

Before using an overlay, confirm the underlying base district and applicable standards in the city’s Blythe Zoning tables and cross-check dimensional rules in Blythe Development Standards. Map boundaries control applicability; when in doubt, verify with the Planning Department per §17.06.020.

What counts as an “overlay” in Blythe’s code

• The zoning list explicitly identifies three overlays: D-O (Redevelopment overlay), HEO (Housing Element Overlay), and C-M-O (Commercial manufacturing overlay) in §17.06.010.
• The D-O provisions and how they apply over the base zoning are detailed in §§17.06.060–17.06.064.
• The HEO’s approval pathway and affordability requirement are contained in §17.08.020.
• The C-M-O is listed among the zones; specific purpose/use rules were not found in the retrieved code excerpts beyond its appearance in the zones list and dimensional table. The dimensional table shows no minimum lot size/width/depth listed for C‑M‑O in §17.10.010.

In addition, Blythe’s Floodplain Management chapter applies to mapped FEMA flood hazard areas across base zones; while not labeled an “overlay zone” by name, it functions as an overlay-style constraint on development within “areas of special flood hazard” under Chapter 17.29. See “Floodplain Management Areas (overlay-like)” below.

District-by-District Breakdown

D-O — Redevelopment Overlay

• Purpose and intent
  • The D-O overlay identifies areas designated by the City and Redevelopment Agency as review areas for compliance with adopted redevelopment plans and standards, with a primary focus on the downtown design implementation program per §17.06.061.
• Typical permitted uses
  • Uses are those permitted by the underlying primary zone; the overlay does not add uses by itself. §17.06.064 states the D‑O symbol is followed by a primary zone symbol on the map and “uses shall be permitted by the primary zone.”
• How approvals work
  • All new uses/structures, any change of use, and any exterior changes or modifications require approval by the City’s Design Review Committee to ensure conformance with the adopted Downtown Design Standards and Architectural Guidelines (see Blythe Design Review) under §17.06.062 and §§17.64.060–17.64.066. Conditional Use Permit requirements of the primary zone still apply if otherwise required per §17.06.063.
• Key dimensional standards
  • The overlay itself does not set specific setbacks/lot coverage; use the underlying district standards (see Blythe Development Standards). Exterior design, signage, and site features are subject to DRC review; signage must also comply with Blythe Signage.
• Where it applies
  • Mapped as “D‑O” followed by the primary zone symbol on the Official Zoning Map per §17.06.064.

HEO — Housing Element Overlay

• Purpose and intent
  • The HEO implements Blythe’s Housing Element by enabling designated sites to approve residential (including mixed-use) projects by right if they meet affordability criteria per §17.08.020.
• Typical permitted uses
  • Any residential development project, including a mixed-use project, on a site designated HEO is a permitted use if the project provides at least 20% of units affordable to lower-income households with long-term affordability covenants (55 years rental/45 years ownership, unless otherwise required by law) per §17.08.020(A).
• How approvals work
  • The Director reviews plans for compliance with objective provisions of the underlying zone, Municipal Code, General Plan, and any applicable specific plans or city regulations/standards; “no other findings shall be required” per §17.08.020(B). Procedures under the Subdivision Map Act still apply if a map is required per §17.08.020(C). Coordinate early with Blythe Land Use for consistency.
• Key dimensional standards
  • The overlay does not replace dimensional standards; objective standards of the underlying zone and citywide standards continue to apply (parking, landscaping, building placement), reviewed ministerially for compliance per §17.08.020(B). See Blythe Parking and Blythe Landscaping and Screening.
• Where it applies
  • Only on parcels mapped as HEO on the Official Zoning Map; confirm designation with Planning per §17.06.020.

C-M-O — Commercial Manufacturing Overlay

• Purpose and intent
  • Not found in retrieved materials beyond its identification as a zone in §17.06.010.
• Typical permitted uses
  • Not found in retrieved materials.
• Key dimensional standards
  • The lot-dimension table in §17.10.010 lists the C‑M‑O with “—” entries (no minimum lot size/width/depth shown). Treat base-zone dimensional standards and general development standards as applicable unless the City indicates otherwise. Verify with the jurisdiction.
• Where it applies
  • Appears as a designated overlay in §17.06.010; specific mapped extents and application details were not found in retrieved materials. Confirm on the Official Zoning Map per §17.06.020.

Floodplain Management Areas (overlay-like)

• Why this matters on an overlay page
  • While not labeled an “overlay zone” by name, Chapter 17.29 applies additional development standards to any site within FEMA “areas of special flood hazard.” In practice this functions like an overlay constraint across all base zones.
• What it requires
  • Development permits, elevation/floodproofing, construction in accordance with mapped base flood elevations, manufactured home standards, and special floodway limitations are required under §§17.29.040–17.29.050. Variances are strictly limited per §17.29.060. Coordinate project design and site planning early; approvals here are distinct from zoning approvals.

Quick-reference: Approvals and Triggers in Blythe Overlays

Practical guidance

• In the D‑O overlay, plan for early design review coordination; the committee checks site plan, architecture, landscape, and signage for consistency with the downtown program before other entitlements proceed per §17.06.062 and §17.64.064.
• On HEO sites, set your program to hit the 20% lower-income threshold and assemble a long-term affordability covenant; your project is a permitted use with Director-level approval if it meets all objective standards per §17.08.020.
• For C‑M‑O, confirm with the City what the overlay changes on your parcel; the code shows it in the zone list and dimensional table, but did not provide a purpose/use section in the retrieved text. Use the Official Zoning Map to verify designation (see §17.06.020) and seek an interpretation if needed.
• If your site is in a mapped flood area, incorporate Chapter 17.29 requirements at concept stage; floodplain rules can drive building pads, first-floor elevations, and allowable encroachments even when zoning otherwise allows development.

Checklist

• Confirm your parcel’s base zone and any overlay symbol on the Official Zoning Map per §17.06.020.
• If mapped D‑O, schedule pre-application with staff and prepare materials for design review per §§17.06.062 and 17.64.064.
• If mapped HEO, structure the project to provide at least 20% lower-income units and prepare affordability restrictions; confirm all objective standards of the underlying zone and applicable city codes are met per §17.08.020.
• If mapped C‑M‑O, request written clarification from Planning on purpose/uses and any supplemental standards; dimensional table shows no minimums listed for this overlay in §17.10.010.
• Check if the site is within FEMA “areas of special flood hazard” and, if so, plan to satisfy Chapter 17.29 (elevation, floodway, manufactured home standards; limited variances).
• Cross-check citywide requirements for parking, landscaping and screening, and any signage standards that may be reviewed as part of overlay approvals.
• If relief is needed, consider variances and exceptions; note floodplain variances are particularly constrained under §17.29.060.

Risks & Ambiguities

Plain-English Summary

Blythe uses overlays to add rules on top of your base zoning. If you’re in the D‑O area (mostly downtown), expect a design review step before you build or change façades. On HEO parcels, a housing or mixed-use project with at least 20% affordable units gets approved by right if it meets all objective rules. The C‑M‑O overlay appears on the city’s zone list, but the retrieved code doesn’t spell out what it changes—so check with the City. Separately, if your site is in a FEMA flood zone, floodplain standards will also apply.

Source References

• §17.06.010 Zones designated (includes C‑M‑O, D‑O, HEO) and zone list; §17.06.020 Official Zoning Map adopted; §17.06.030 Map boundary uncertainty rules.
• §17.06.060 Redevelopment overlay zone; §§17.06.061–17.06.064 D‑O purpose, development manner, CUPs, and map designation.
• §17.08.020 Housing Element Overlay (HEO) — permitted use, 20% affordability, director review, Subdivision Map Act note.
• §17.10.010 Lot and Building Dimensions (table shows C‑M‑O and D‑O entries; C‑M‑O with “—” minimums).
• §§17.64.060–17.64.066 Design Review Committee purpose, composition, scope, and process (downtown design).
• Chapter 17.29 Floodplain Management — applicability, administration, flood hazard reduction standards, variances.

Retrieved passages

• Blythe Zoning Code (Section 17.12.040) High relevance show source text
• Blythe Zoning Code (§ 1) Medium relevance show source text
• Blythe Zoning Code (§ 6.03) Medium relevance show source text
• Blythe Zoning Code (section shall) Medium relevance show source text
• Blythe Zoning Code (chapter which) Medium relevance show source text
• Blythe Zoning Code (Title 17) Medium relevance show source text
• Blythe Zoning Code (§ 2) Medium relevance show source text
• Blythe Zoning Code Medium relevance show source text
• Blythe Zoning Code (Section 17.29.050) High relevance show source text
• Blythe Zoning Code (§ 1) High relevance show source text
• Blythe Zoning Code (Section 17.29.040) Medium relevance show source text
• Blythe Zoning Code (Section 17.64.060) Medium relevance show source text
• Blythe Zoning Code (§ 4) Medium relevance show source text
• Blythe Zoning Code (Section 17.29.050) Medium relevance show source text
• Blythe Zoning Code (title for) Medium relevance show source text
• Blythe Zoning Code (Section 17.29.040) Medium relevance show source text
• CBC § 1 (§ 1) Medium relevance show source text
• Blythe Zoning Code (§ 3) Medium relevance show source text
• Blythe Zoning Code (section are) Medium relevance show source text
• Blythe Zoning Code (§ 1) Medium relevance show source text

Cited sections

• §17.06.010 Zones designated (includes C‑M‑O, D‑O, HEO) and zone list; §17.06.020 Official Zoning Map adopted; §17.06.030 Map boundary uncertainty rules. (§17.06.010)
• §17.06.060 Redevelopment overlay zone; §§17.06.061–17.06.064 D‑O purpose, development manner, CUPs, and map designation. (§17.06.060)
• §17.08.020 Housing Element Overlay (HEO) — permitted use, 20% affordability, director review, Subdivision Map Act note. (§17.08.020)
• §17.10.010 Lot and Building Dimensions (table shows C‑M‑O and D‑O entries; C‑M‑O with “—” minimums). (§17.10.010)
• §§17.64.060–17.64.066 Design Review Committee purpose, composition, scope, and process (downtown design). (§17.64.060)
• Chapter 17.29 Floodplain Management — applicability, administration, flood hazard reduction standards, variances. (Chapter 17.29)
• Blythe_ZoningCode.md

• Official Blythe code library