In Topeka, there is no single municipal code section that automatically requires a formal “sewer capacity study” for every individual connection the way some other cities do.

Requirements focus more on availability, adequacy, permitting, and design standards. Capacity is evaluated as part of the review process, especially for new development or larger projects.

What the Topeka code and standards actually say

Subdivision / development side (Topeka Municipal Code Chapter 18.40) Lot sizes and shapes are determined by the availability and adequacy of public sewer (and water) facilities. The subdivider must contact the Department of Public Works about sewer availability and specifications. If public sewer is not available, Health Department standards apply for private systems. Approval hinges on the system being able to serve the proposed development.

Connection side (Chapter 13.20 – Sewers)

• Connection to the public sanitary sewer is required under certain conditions (septic nuisance, ownership change, building permit work, or within a set time after the sewer is installed nearby).
• A permit from the City Engineer / Utilities Department is required before any connection.
• System connection fees are charged based on meter size or projected flows.
• Work in rights-of-way must follow city standards and typically involves licensed plumbers; the city itself often performs the actual tap.

Design standards (City of Topeka Design Criteria Manual, Section 1.4 – Sanitary Sewer Design Criteria) This is the key technical document for capacity-related requirements. It is available online through the City’s Design & Drafting / Engineering page.

Key points from Section 1.4:

• Design must conform to the current City of Topeka wastewater plan, the WPCF/ASCE Manual of Practice No. 9 (Design and Construction of Sanitary and Storm Sewers), and Kansas Department of Health and Environment (KDHE) minimum standards, except as modified by the city.

• Design period: Lateral and main sewers are sized for the estimated ultimate population of the area served (per the Facilities Plan). Interceptor sewers are sized for at least 25 years of expected development. Staged construction may be allowed for major lines.

• Design flows (when measured data are not available):

  Type of Development	Average Flow	Peak Flow*
  Residential	70 gpcpd	300 gpcpd
  Commercial	5,000 gpapd	7,500 gpapd
  Industrial	5,000 gpapd	7,500 gpapd

  (*Peak flow includes wet-weather inflow and infiltration allowance. gpcpd = gallons per capita per day; gpapd = gallons per acre per day.)

• Pipe sizing uses the Manning equation with n = 0.013 (unless a variance is approved). Minimum public gravity sewer size is 8 inches.

• Minimum velocity (full or half-full) is 2 feet per second; maximum is 10 feet per second. Minimum slopes are specified by pipe diameter to achieve the 2 fps velocity.

• Deviations require approval by the Water Pollution Control Superintendent and City Engineer.

Practical reality for connections and studies

• Single residential connections: Usually handled through a standard sewer connection permit and fee. The city reviews the application against known system conditions. A formal developer-prepared capacity study is rarely required.
• Larger developments, subdivisions, commercial/industrial projects, or areas with known constraints: The city (Utilities / Public Works / Engineering) will evaluate whether downstream capacity is adequate. They may require the applicant’s engineer to submit flow calculations, a capacity analysis of downstream segments, or other supporting information based on the Design Criteria above. The city maintains its own collection-system models and facility plans and has performed citywide capacity-related work (including treatment-plant capacity reviews).
• There is no publicly posted, detailed “checklist for a sewer capacity study” specific to Topeka like some cities publish. Requirements are driven by the Design Criteria Manual, the wastewater plan, and case-by-case review by city staff.

Where to find the documents online

• Design Criteria Manual (including Section 1.4 Sanitary Sewer Design Criteria): Available via the City of Topeka Public Works / Design & Drafting page (search “Design Criteria Manual” or “Design Right of Way” on topeka.gov).
• Municipal Code chapters on sewers and subdivisions: topeka.municipal.codes.
• Connection permits, fees, and installation standards: City of Topeka Utilities Department materials.

Bottom line for Topeka: You connect to Topeka’s system and must meet its availability, permitting, fee, and design standards. A formal capacity study is not automatically mandated by code for every connection, but the Design Criteria require sewers (especially new or extended ones serving development) to be sized for ultimate flows and adequate capacity. For anything beyond a simple residential tap, contact Utilities / Public Works early—they decide what analysis, if any, is needed based on location and proposed flows.