Improvement Plans

Public Improvement Plans are prepared by a Registered Civil Engineer licensed to practice within the State of California. They show how improvements are to be constructed within City rights-of-way and easements and also generally include improvements in private property areas as well.


The improvements include, but are not limited to, street improvements, including street lighting and undergrounding of existing or proposed overhead utilities, sanitary sewer, water systems, storm drainage, and grading.

When Public Improvement Plans Are Required

The requirement to prepare and submit Public Improvement Plans typically arises during the course of review of a development application, most commonly subdivisions, conditional use permits, design review, and building permits.

Not every such application is required to submit plans; the decision whether or not plans must be submitted is made by staff in Engineering Development Services. Sometimes the conditions of approval placed upon a development application (for example, a requirement to widen a street or extend a storm drain) are in themselves enough to trigger the need for plans, and then the requirement to submit plans is also imposed.

Approval Process

Blueprints of Public Improvement Plans (normally six sets, eight if review by the Department of Recreation and Parks is necessary) are initially submitted by the applicant’s engineer to Engineering Development Services. Following a cursory check to make sure that all necessary items have been submitted, the blueprints are distributed (in sets of two) for review to the Planning Division, the Utilities Department, and the Recreation and Parks Department (if appropriate). Two copies are retained by Engineering Development Services.

Each plan check entity then reviews the blueprints. Required changes are marked on the prints in colored pen or pencil. One set of marked up prints is returned to the private engineer and one set is retained for use in review when new prints of the corrected plans are resubmitted. All of the exchange of prints takes place through Engineering Development Services.

Process Cycles

The process of submittal, review, mark-up return, correction, and resubmittal continues until all the plan check entities are satisfied that their concerns have been adequately addressed. Typically, two or three cycles are required. A second cycle (or check) usually doesn’t take as long as the first. The goals of the various entities for completing the checks are 42 calendar days (6 weeks) for a first check and 21 calendar days for subsequent checks.

Final Approval

Once the plans are determined to be satisfactory, the private engineer submits mylar originals for signature. The plans are initialed by various plan check entities and then forwarded to the City Engineer for signature approval. Once approved, the original drawings are assigned a City file number and returned to the private engineer. The private engineer then has 17 blueline copies of the plans made up and resubmits the original mylars and blueline copies, all of which are then utilized by a variety of City and public utility entities as a record of improvements to be installed.

It should be noted that, independent of City review, a separate review of the plans is required by the Sonoma County Water Agency, PG and E, and Pacific Bell, and their approvals in writing are required before the City will approve the plans.