A BILL to amend the Code of Virginia by adding in Article 4 of Chapter 2 of Title 33.2 a section numbered 33.2-280.3 and by adding in Article 2.6 of Chapter 3.1 of Title 62.1 a section numbered 62.1-44.15:85, relating to precipitation design standards; non-stationary precipitation; climate-adjusted rainfall.
HB1356 would require Virginia state agencies and political subdivisions to update infrastructure design standards to account for climate-adjusted precipitation, also described as non-stationary precipitation or climate-adjusted rainfall. The bill directs the State Water Control Board to serve as the lead agency for establishing and maintaining precipitation design standards, using the latest NOAA precipitation frequency estimates and accounting for observed and projected increases in rainfall intensity, frequency, and duration. It also requires the Department of Transportation to incorporate these values into the design and construction of stormwater facilities, culverts, bridges, and other transportation infrastructure, and to update manuals such as the VDOT Drainage Manual and Structure and Bridge Manual.
The bill further requires annual review of stormwater and related technical criteria, authorizes the Board to adopt standards or issue guidance through an abbreviated rulemaking process, and sets a deadline of July 1, 2027, for relevant manuals and design standards to be updated. Until NOAA Atlas 15 is published and adopted, the bill requires interim guidance that increases NOAA Atlas 14 precipitation values by at least 20 percent for design purposes. It also allows localities and regional transportation authorities to adopt more stringent standards and directs agencies to identify and pursue funding sources, including federal resilience and infrastructure programs, to help implement the new requirements.
HB1356 would amend Virginia law by adding new sections to Titles 33.2 and 62.1 that impose statewide climate-adjusted precipitation requirements on transportation and water-related infrastructure design. It would affect the Department of Transportation, the Department of Environmental Quality, the State Water Control Board, localities, political subdivisions, and public-private partnership projects by requiring updated manuals, standards, and design practices for stormwater management, floodplain management, culverts, bridges, and other public infrastructure. The bill also creates an implementation timeline and authorizes interim regulatory action to speed adoption of the new standards.
The available legislative history suggests the bill was treated cautiously rather than as a highly controversial measure, with no recorded floor votes or committee testimony provided in the materials. Its referral to the Agriculture, Chesapeake and Natural Resources Committee and subsequent continuation to the next session by voice vote indicate that the bill did not advance immediately and may have required further consideration. Overall, the bill appears to reflect a policy interest in flood resilience and climate adaptation, with no explicit evidence in the record provided of organized support or opposition.
The main points of potential contention are the mandate to use climate-adjusted precipitation values, the requirement to increase Atlas 14 values by at least 20 percent until Atlas 15 is available, and the cost and administrative burden of updating statewide design manuals and infrastructure standards. Agencies, localities, and transportation authorities may differ over how quickly standards should change, what projection methods should be used, and who should bear implementation costs. The bill’s allowance for more stringent local standards may also raise concerns about consistency across jurisdictions, while its reliance on NOAA data and climate projections could be debated by those skeptical of the underlying assumptions or the need for mandatory statewide updates.