City engineer leads plan‑reading training for Planning Board

City Engineer Joe Levarier led a February 4 training session for the Saco Planning Board on reading civil engineering plans, interpreting topography and contours, and evaluating stormwater treatment options.

Levarier told board members the session was intended to give them “tips and tricks” to read plan sets more efficiently so they can identify constraints such as wetlands, setbacks, test pits and existing utilities before a public hearing. He walked the board through an older city plan set for a Foss Road public‑services site to show how sheets are organized and where reviewers should look first.

The training focused on a handful of recurring review tasks: identifying the plan index and legend, finding existing conditions (wetlands, vernal pools, soils borings), reading contour intervals and tracing watershed flow, and separating layout, grading and utility plans so each remains readable. Levarier recommended highlighting major contours (for example, every 5 or 10 feet) and using aerial basemaps to make existing features easier for reviewers and neighbors to visualize. “Water flows perpendicular to contours,” Levarier said, urging members to trace contours to determine where swales and catch basins will carry runoff.

Levarier used the sample set to demonstrate common sources of confusion. He showed how raised berms and ditch lines can look similar on a plan and said reviewers should check contour labels (e.g., 30, 35) to tell whether a feature is a high point or a flow line. He also emphasized checking for clear curb symbols and end‑of‑curb notes, and asked members to request that applicants separate grading or utility drawings when page layouts become overcrowded.

The session included extended discussion of stormwater treatment options. Levarier described the tradeoffs among detention ponds, wet ponds, gravel wetlands and chambered underground systems and said some BMPs increase site fill because treatment must sit above the outlet. He noted gravel wetlands (which keep a saturated zone and can allow a higher outlet) as a useful option on constrained sites and cited a recent retrofit on Industrial Park Road where the city converted an older detention basin to a gravel wetland at municipal expense.

On pervious (porous) pavement, Levarier stressed maintenance needs: pervious surfaces can infiltrate stormwater but are prone to clogging and require periodic vacuuming. He said pervious pavement is appropriate in some locations but questioned reliance on it where long‑term maintenance by private homeowners or associations is uncertain. “If you’re doing pervious pavement then you’re talking about someone who’s coming in and vacuuming,” Levarier said, adding that municipal acceptance of a BMP often depends on who will maintain it.

Levarier described the city’s approach to long‑term maintenance: when city water is conveyed into a stormwater facility, the city generally takes the facility over so it can ensure ongoing maintenance; on private developments the developer or HOA usually remains responsible. He also explained the city’s urban‑impaired‑stream requirements and fee option (CFUP) for projects that cannot meet higher treatment standards on‑site: projects that cannot meet the urban impaired stream standard sometimes may contribute to the Compensation Fee Utilization Plan to fund off‑site mitigation. Levarier said the state NRPA minimum buffer is 75 feet but that agencies such as IF&W often recommend a 100‑foot buffer, and he said planning staff regularly ask applicants to stay out of those buffers or place them into open‑space lots.

Board members asked practical review questions: Jeff Bruscheau asked about best practices for curb cuts and sidewalk relationships; Levarier said curbs direct water and that curb/sidewalk details should be clear on plans. Members discussed turning‑movement diagrams for fire and delivery access; Levarier said the applicant normally provides vehicle turning templates and that the burden is on the applicant to demonstrate acceptable maneuvers. The group also discussed how to evaluate proposed grading relative to existing benchmarks so neighbors can see how road and lot grades will change.

Levarier offered follow‑up training and printed plan sheets for members to examine in small groups. “If there’s other things that you want to cover another time, just let me know,” he told the board. Chair Matt Provencal and several board members thanked Levarier for his memos and presentations and asked staff to schedule future sessions.

The presentation supplied the board with review‑focused guidance rather than a change in policy; no formal board action was recorded.