Open space and environment

Flooding and stormwater

FEMA's revised flood maps for Hillsborough take effect on November 13, 2026, the date FEMA set in an August 2026 Federal Register notice. The township must replace its floodplain rules to stay in the federal flood insurance program, and Ordinance 2026-10 has its hearing on November 10. Work since Ida includes a rebuilt basin, a Blue Acres buyout agreement and a state-required watershed plan.

Checked against the primary record on . Every figure on this page is sourced at the foot of the article.

Flood-map ordinance hearing Nov 10; new maps Nov 13 Last moved

What happens next

Public hearing on Ordinance 2026-10 at a special Township Committee meeting on Tuesday, November 10, 2026, at 6:30 pm, Peter J. Biondi Municipal Building, 379 South Branch Road. Check your address on FEMA's flood map before the new maps take effect.

Hillsborough’s flooding comes from its rivers and streams: the Millstone along River Road, the Raritan and its South Branch, and Royce Brook. The remnants of Ida in September 2021 are the storm the township’s records keep returning to.

New flood maps. FEMA released revised preliminary flood maps for Hillsborough on March 7, 2025. Two map panels change, 34035C0137F and 34035C0141F; the others stay as they are. FEMA’s final notice, published in the Federal Register on August 6, 2026, sets the effective date as November 13, 2026, and the township’s draft Ordinance 2026-10 adopts the maps with that date. The ordinance replaces Chapter 172, “Flood Damage Prevention”, to keep Hillsborough in the National Flood Insurance Program, and it makes the Township Engineer the Floodplain Administrator. It was on the October 27 agenda for introduction. Minutes of that meeting are not yet posted, so the vote is not confirmed. A special meeting on November 10 is set for the hearing.

Since Ida. The township signed the state’s Blue Acres agreement in June 2025 and will maintain the lots of any flood-damaged homes the state buys and demolishes. The Committee was told that 11 owners had applied. A detention basin behind Harvard Way, damaged by Ida, was rebuilt by December 2025. In August 2025 the Committee adopted a long-range drainage plan and hired the engineering firm Pennoni, for up to $134,000, to start the watershed plan the state requires; no report has been posted. A Fox Chase Pond shoreline restoration, with Rutgers, was on the June 2026 agenda.

Residents can speak at the November 10 hearing, look up their address on FEMA’s map, and ask the Engineering Department about flood zone permits and Blue Acres.

Flooding and stormwater, explained

Timeline

Each dated event on this issue, oldest first, linked to the full sourced entry.

  1. Milestone Remnants of Ida flood HillsboroughThe remnants of Hurricane Ida struck on September 1–2, 2021. Township records tie Ida to a badly damaged detention basin behind Harvard Way, to Blue Acres buyout applications and to a revised FEMA flood map panel.
  2. Resolved FEMA releases revised preliminary flood maps for HillsboroughFEMA released revised preliminary Flood Insurance Rate Maps for Hillsborough, Bedminster, Branchburg and Union Township in Hunterdon County.
  3. Resolved Committee told the revised map changes the River Road area near Studdiford bridgeThe Committee was told the township had received a preliminary revised FEMA map for panel 137, covering parts of River Road by the Studdiford bridge, with a minor revised flood area due to Ida. Comments were due April 7.
  4. Resolved Township joins the state Blue Acres buyout program and adopts the county hazard planThe Committee approved an agreement with NJDEP Blue Acres under which the township maintains the lots of flood-damaged homes the state buys, and adopted the 2025 Somerset County Hazard Mitigation Plan. The Committee was told 11 owners had applied.
  5. Resolved Committee adopts a long-range drainage plan and hires Pennoni for the watershed inventoryThe Committee adopted a resolution creating a long-range plan to address drainage problems and hired Pennoni, for up to $134,000, for the Watershed Inventory Report the state requires.
  6. Resolved FEMA opens the 90-day appeal period on the new flood mapsThe 90-day period to appeal or comment on FEMA's revised preliminary flood maps for Hillsborough opened.
  7. Resolved Ida-damaged Harvard Way basin rebuiltThe Committee was told that the detention basin at Harvard Way and the Hillsborough Campus, severely damaged by Ida, had been reconstructed to its original design.
  8. Resolved Grant application for a Willow Road green infrastructure studyThe Committee supported an application for a $2,000 Sustainable Jersey/PSEG grant for a Willow Road Green Infrastructure Feasibility Study (R-98-2026), as part of a unanimously approved consent agenda.
  9. Pending Fox Chase Pond shoreline restoration contract on the agendaThe agenda carried R-210-2026, a contract of up to $41,600 with West Jersey Lawn Care for excavation for the Fox Chase Pond Shoreline Restoration Project, with the Rutgers Cooperative Extension Water Resources Program.
  10. Resolved Engineering reminders on sump pumps and private stormwater systemsThe township reminded residents that sump-pump lines causing hazardous street flooding or icing must be relocated, and that businesses and HOAs must maintain private stormwater systems and file an annual certification.
  11. Pending Planning Board considers support for a flood-resilience transportation planning grantThe Planning Board agenda included a letter of support for the township's "Green Hills Transportation Resilience & Emergency Access Planning Project," an FY24–FY26 PROTECT planning grant.
  12. Pending New flood ordinance adopting FEMA maps scheduled for introductionOrdinance 2026-10, which replaces the township's flood rules and adopts FEMA's new maps dated November 13, 2026, was on the agenda for introduction. A special meeting on November 10 was set for the hearing.
  13. Pending Public hearing on the flood ordinanceThe Township Committee has scheduled a special meeting at 6:30 pm for the public hearing and final vote on Ordinance 2026-10, three days before FEMA's new maps take effect.
  14. Pending FEMA's revised flood maps take effectFEMA's revised Flood Insurance Study and maps for Somerset County, including Hillsborough, take effect. FEMA set the date in a Federal Register notice of August 6, 2026.

Explainers

  • Flooding and Stormwater in Hillsborough: New Flood Maps, a New Ordinance, and the Work Since Ida

    FEMA's revised flood maps for Hillsborough take effect on November 13, 2026, the date FEMA set in an August 2026 Federal Register notice. Ordinance 2026-10, which adopts the maps and rewrites the township's flood rules, has its hearing on November 10. Since Ida in 2021 the township has rebuilt a damaged basin, joined the state's Blue Acres buyout program, adopted a long-range drainage plan and started a state-required watershed plan.

Documents

The township's own records on this issue. Each links to the official copy.

Meetings

  • Township Committee — October 27, 2026

    The agenda carried the introduction of Ordinance 2026-10, which replaces the township's flood damage prevention chapter and adopts the new FEMA flood maps, with a hearing set for a November 10 special meeting. The minutes are not yet posted, so outcomes are not confirmed here.

  • Planning Board — October 8, 2026

    The agenda carried a letter of support for the township's Green Hills transportation-resilience and emergency-access planning grant, and proposed completeness-review procedures. The minutes are not yet posted, so outcomes are not confirmed here.

  • Township Committee — August 25, 2026

    The consent agenda covered rail quiet-zone recertification, county road striping and materials for Montgomery Road. The Committee adopted the $43,000 phone-system ordinance and introduced new wrecker fees. Engineering reminded residents about sump pumps and stormwater certification.

  • Township Committee — June 23, 2026

    The longest meeting of the year. The agenda carried the hearings on Ordinance 2026-07, the Sunnymead Landfill Redevelopment Plan, and Ordinance 2026-06, plus a $41,600 contract for the Fox Chase Pond shoreline restoration. The minutes are not yet posted, so outcomes are not confirmed here.

  • Township Committee — May 26, 2026

    Ordinance 2026-07, the Sunnymead Landfill Redevelopment Plan, was introduced unanimously, along with an engineering-fees ordinance. The consent agenda renewed police body-camera service and approved a stormwater maintenance agreement.

  • Township Committee — May 12, 2026

    A short meeting with a four-item consent agenda, passed unanimously. In public comment a resident said the state's funds for restoring Fox Chase Pond must be used by December 31, 2026.

  • Township Committee — February 24, 2026

    The Committee awarded the $593,000 police department renovation, bought two police drones, settled the Volkert lawsuit tied to the former Belle Mead depot solar project, and adopted Ordinance 2026-01 on industrial-district uses.

  • Township Committee — December 9, 2025

    The hearing on Ordinance 2025-17, the Millburn-area no-parking rules, was tabled unanimously after resident opposition. The township reported a $505,903 NJDOT grant for Farm Road and the rebuilt Harvard Way detention basin that Ida had damaged.

Sources for this overview

  1. Township Committee agenda packet, October 27, 2026 (draft Ordinance 2026-10, pp. 56+; R-335-2026) LocalWhy copy of Township Committee agenda packet, October 27, 2026 (draft Ordinance 2026-10, pp. 56+; R-335-2026) (opens in a new tab)
  2. FEMA, "Public Invited to Review Flood Maps in Hunterdon and Somerset Counties, New Jersey," August 14, 2025
  3. FEMA, "Final Flood Hazard Determinations," Federal Register, August 6, 2026 (FR Doc. 2026-15942; Somerset County, effective November 13, 2026) LocalWhy copy of FEMA, "Final Flood Hazard Determinations," Federal Register, August 6, 2026 (FR Doc. 2026-15942; Somerset County, effective November 13, 2026) (opens in a new tab)
  4. Township Committee minutes, August 12, 2025 (long-range drainage plan; Pennoni watershed inventory) LocalWhy copy of Township Committee minutes, August 12, 2025 (long-range drainage plan; Pennoni watershed inventory) (opens in a new tab)
  5. Township Committee minutes, June 24, 2025 (Blue Acres MOU; Harvard Way basin) LocalWhy copy of Township Committee minutes, June 24, 2025 (Blue Acres MOU; Harvard Way basin) (opens in a new tab)
  6. Township Committee minutes, December 9, 2025 (Harvard Way basin rebuilt) LocalWhy copy of Township Committee minutes, December 9, 2025 (Harvard Way basin rebuilt) (opens in a new tab)
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