A wide angle panoramic photo from July 25, 2022, shows the controversial watershed area and sand pit across from Gracelawn Road, bottom in Auburn. Russ Dillingham/Sun Journal

AUBURN — The Maine Drinking Water Program is reviewing the latest data regarding the Lake Auburn watershed boundary off Gracelawn Road and will make a determination on where it believes the boundary should be.

A map in the newest report from consultant CDM Smith shows the Gracelawn Road parcel at center of a debate over watershed rules. The state Drinking Water Program is reviewing a proposed new watershed boundary, shown in light blue. Screenshot of map

The decision could have ripple effects in Lewiston-Auburn because it will likely determine the level of housing development that can occur on the site, as well as have a potential impact on the pending lawsuit between Lewiston and the Auburn Water District.

According to Mike Broadbent, Auburn Water District superintendent, the most recent study data from a consultant has been sent to the state, where the Maine Drinking Water Program will make a determination on an acceptable watershed boundary.

The boundary, which follows mostly along Gracelawn Road, has previously been recommended to shift northward toward the lake based on previous data on groundwater and stormwater flows. The city of Auburn rezoned the land based on the previous recommendation, leading to a proposed development by property owner John Gendron.

However, the prospect of new development and questions about its impact to the lake has led to a prolonged debate, and lawsuit, over whether the watershed boundary should be changed.

The most recent data from consultant CDM Smith says that a conservative watershed boundary “can be established without further investigations,” but that if the boundary were to include more area northward, it would require more data to make a similar conclusion about groundwater flow “with certainty.”

Broadbent described the state’s recommended boundary as “an irrefutable boundary,” where any water south of the boundary does not go toward the lake and anything north would have to be further studied.

Following the newest report, Broadbent co-authored a letter to the state with Lewiston Water Division Superintendent Kevin Gagne, asking them to review and consider the approval of the previously recommended boundary.

Gendron, who operates part of the land as an active gravel pit, has previously proposed an 1,100-unit development on the site utilizing 88 acres. The entire site owned by Gendron is 148 acres, but it’s unclear how a new boundary, if implemented, would impact the development proposal.

Meanwhile, Broadbent said a new ad hoc committee has been formed among the two cities, the water districts and the Lake Auburn Watershed Protection Commission, to consider further changes to watershed rules.

He said a LAWPC letter this spring outlined several recommended changes for the Auburn Water District to consider, but that he felt a committee featuring members of all parties was the best way forward.

The recommendations range from siting new septic systems and monitoring surface and groundwater at the Gracelawn parcel, to recommendations that would impact upper watershed towns in an effort to reduce the amount of nutrients entering the lake.

Because Lake Auburn is an unfiltered water source, the cities hold a waiver from filtration that allow it to deliver the water unfiltered as long is it continues to meet certain standards.

The communitywide debate over watershed rules and development has unfolded as water quality at the lake has fluctuated due to warmer winters and more stormwater runoff.