Texas Drainage Criteria Directory

Each link opens the publisher’s own site. Last checked November 4, 2026. This directory does not say which document applies to a project. A publisher can change a document at any time, so confirm the current edition and any local amendments with the reviewing agency.

Cities

Jurisdiction	Document	Edition, as shown	Note
City of San Antonio	Storm Water Design Criteria Manual	Not confirmed	The city page links a January 2016 manual and an Atlas 14 amendment revised April 2019. A city checklist refers to a January 2022 edition. Confirm the current edition with the city.
City of Austin	Drainage Criteria Manual	Not shown on the page	The city page links to the manual on Municode, where its edition is shown.
City of Houston	Infrastructure Design Manual	Effective March 2, 2026	Chapter 9 is Stormwater Design Requirements. The city page describes which plans follow which edition.
City of Dallas	Drainage Design Manual	September 2019	The city page also lists the 1993 manual.
City of Fort Worth	Stormwater Criteria Manual	In effect from July 15, 2024	The city page also links the 2015 manual.
City of Corpus Christi	Infrastructure Design Manual	March 2022	Chapter 3 is Stormwater Design Requirements. The department also posts a draft Drainage Design Manual appendix dated December 2024.

Counties

Jurisdiction	Document	Edition, as shown	Note
Harris County	Regulations of Harris County, Texas for the Approval and Acceptance of Infrastructure	Adopted December 18, 2018; updated October 10, 2023	The county page also lists a September 1, 2023 version for use with the 2017 Standards and Specifications.
Bexar County	Flood Damage Prevention Court Order Floodplain regulation	Effective August 22, 2023	A floodplain regulation, not a drainage manual. We did not find a separate county drainage manual.
Bexar County	Bexar County Regulations for Storm Water Pollution Prevention Water quality	Passed November 18, 2025
Travis County	Chapter 482. Travis County Development Regulations	Amendments through October 28, 2025	The county subdivision page points drainage designs to the City of Austin Drainage Criteria Manual.
Fort Bend County	Drainage Criteria Manual	Revised 2011	The page also lists an Interim Atlas 14 manual (effective January 1, 2020, updated September 2021) and a draft manual not in force until adopted.
Montgomery County	Montgomery County Drainage Criteria Manual	Adopted August 26, 2025; amended September 17, 2026

Flood control districts and regional agencies

Jurisdiction	Document	Edition, as shown	Note
Harris County Flood Control District	2019 Atlas 14 Policy Criteria and Procedures Manual	Not shown on the page	2019 is in the title; the page shows no other date.
Harris County Flood Control District	Hydrology and Hydraulics Guidance Manual	Not shown on the page
North Central Texas Council of Governments	iSWM Criteria Manual	December 2009, revised January 14, 2015	The page marks this version current and earlier ones legacy.

State agencies

Jurisdiction	Document	Edition, as shown	Note
Texas Department of Transportation	Hydraulic Design Manual	Revised September 2019
Texas Commission on Environmental Quality	Complying with the Edwards Aquifer Rules: Technical Guidance on Best Management Practices (RG-348) Water quality	Revised July 2005	The page also lists 2009 errata and 2017 and 2018 addenda.

Where to read four common items

For the documents we have read: design frequency, detention release, minimum time of concentration and street spread, each with the section to read. These are short summaries in our words, not the rule itself, and most of these rules have exceptions by road class, area or date. Read the section. Other documents above were not read for this.

City of San Antonio: Storm Water Design Criteria Manual January 2016 text; see the edition note above

Design frequency

Storm drains: ultimate 25-year under 100 ac of cumulative area, ultimate 100-year above it, with the grade lines below the gutter and top of curb. (§7.3.1, p. 7.15)

Detention release

New development at or below predevelopment peaks for the 5-, 25- and 100-year, except as provided in §4.3.1. Redevelopment at or below existing conditions. (§4.3.7, §4.3.8, p. 4.6)

Minimum time of concentration

For the overland segment only, not total Tc: 5 to 20 minutes. (§5.4.1, p. 5.3)

Street spread or ponding

By road class. Arterials keep one lane each way passable, 0.30 ft in that lane in the 25-year ultimate. (§6.2.1, pp. 6.1-6.2)

City of Dallas: Drainage Design Manual September 2019 manual

Design frequency

1% annual chance storm for streets, inlets and laterals. Alleys contain it within the pavement. (§3.2, p. 22; §3.6.3)

Detention release

No increase in peak discharge or erosive velocity against existing conditions, for the 1%, 2%, 10% and 50% annual chance storms. Small infill and some roadway outfalls are exempt; a downstream assessment changes the storms. (§2.3.1, p. 16; Table 2.2)

Minimum time of concentration

A computed Tc under 10 minutes is taken as 10 minutes. (§2.2.1.3, p. 10)

Street spread or ponding

By road class. Minor arterial and lower: 6 in or top of curb. Principal arterial: one lane open each way. (§3.2.1, Table 3.1)

City of Corpus Christi: Infrastructure Design Manual Chapter 3, March 2022

Design frequency

By road class: local and collector 5-year, arterial 25-year, highway and freeway 50-year. Underground: 5-year under 200 ac, 25-year 200 to 500 ac, 50-year over 500 ac. (§3.03 Level of Protection, Ch. 3 pp. 1-4)

Detention release

Post-development runoff released at no more than the pre-developed peak; no return periods in this rule. Regional detention may substitute. (§3.05, Ch. 3 p. 15)

Minimum time of concentration

None found in the parts we read.

Street spread or ponding

No width. Local: the 5-year must not pond across the roadway at inlets above the curb line. Arterial and highway: not across more than one lane. (§3.03, Ch. 3 pp. 1-2)

Harris County: Regulations of Harris County, Texas for the Approval and Acceptance of Infrastructure regulations updated October 10, 2023

Design frequency

Storm sewers on the 2-year rainfall in newly developed areas, with the hydraulic gradient below the gutter line. Redevelopment differs, and Houston guidelines also apply in its ETJ. (§6.02.2, pp. 27, 30)

Detention release

Not a pre-development rule: limited to the capacity allotted to the tract in the receiving sewer, or a share of a roadside ditch. HCFCD criteria prevail at an HCFCD channel. (§6.03.4, p. 42)

Minimum time of concentration

No minimum stated. Rational Method: Tc = 10 A^0.1761 + 15 minutes, A in acres. (§6.02.1, p. 25)

Street spread or ponding

No spread limit. Extreme event ponding: 6 in above top of curb at high points, 18 in at low points. (§6.02.3, p. 34)

Travis County: Chapter 482. Travis County Development Regulations amendments through October 28, 2025

Design frequency

No stand-alone return period here: design meets the City of Austin Drainage Criteria Manual, which we did not read for this. (§482.207(b), p. 71)

Detention release

No numeric peak limit found. Prevent additional identifiable adverse flooding, and control the 2-year peak on site. (§482.207(a), p. 71)

Minimum time of concentration

None found in the parts we read.

Street spread or ponding

No limit found. Plans show the street ponding width for the 100-year. (§482.301, p. 109)

Fort Bend County: Drainage Criteria Manual manual revised 2011 and Interim Atlas 14 manual (2019, revised 2021)

Design frequency

No base return period stated. Added checks: 25-year grade line at the gutter for the part draining 100 to 200 ac, 100-year below natural ground over 200 ac. (§5.2.3, pp. 5-3, 5-4)

Detention release

Interim manual: not above pre-development discharges for the Atlas 14 10-year and 100-year (its text has a blank between them). Manual: under 50 ac, 0.125 cfs per acre in the 100-year. Date and project rules apply. (Interim §4, p. 4; §6.4.1, p. 6-3)

Minimum time of concentration

None found in the parts we read.

Street spread or ponding

No spread limit. Ponding in a new street in the 100-year: the lowest of 1 ft above natural ground, 1 ft above top of curb, or 1 ft below the lowest slab. (§5.4.1, p. 5-10)

Montgomery County: Montgomery County Drainage Criteria Manual September 2026 manual

Design frequency

Storm sewer 5-year up to 100 ac of cumulative service area, 100-year above it, with the grade line at or below the gutter flow line. (§5.1.1, p. 51; §5.2.1, p. 52)

Detention release

5-, 10- and 100-year mitigated, with post-developed peaks below pre-developed. A simplified rate for 20 ac or less. Some small projects are exempt. (§6.2, p. 57; §6.3, pp. 59-66)

Minimum time of concentration

Minimum 10 minutes. (§2.2, p. 5)

Street spread or ponding

No spread limit. Ponding in the developed 100-year: the lowest of 12 in above top of curb, 1 ft below the lowest floor, or natural ground at the right-of-way. (§5.4.1, p. 55)

North Central Texas Council of Governments: iSWM Criteria Manual December 2009, revised 1/14/2015. Each city may change these

Design frequency

Streets, on-grade inlets and storm drain pipes: 25-year, 24-hour conveyance storm. Low points and right-of-way: 100-year, 24-hour. (Table 1.2, p. 5; §3.6.2)

Detention release

By option: modify downstream conveyance, show no downstream increase, or hold pre-development peaks on site. (§3.5.2, p. 30)

Minimum time of concentration

None found in the parts we read.

Street spread or ponding

Collectors, arterials and thoroughfares: 8 ft or one travel lane. Residential: curb depth or 6 in at the gutter. In the conveyance storm. (§3.6.2, Table 3.7)

A jurisdiction not listed here may still have criteria; ask its reviewing office. Tell us about a broken link or a newer edition.