Editing Columbia, Maine (section)

===Watersheds===
Within its boundaries, the town of Columbia has one [[great pond]], Schoodic Lake (also in Cherryfield and T18 MD BPP). The water resources of Columbia are characterized primarily by the [[Pleasant River (Pleasant Bay)|Pleasant River]] and several other watersheds.

The headwaters of the [[Harrington River]] rise in the western part of Columbia, comprising the sub-watersheds of Trout Brook, Great Marsh Stream and several smaller tributaries leading directly to the Harrington River. The northwestern part of this watershed contains Pineo Ridge and a large sand and gravel [[aquifer]], with potential yields of than 50 gallons per minute. The southern part of this watershed is primarily forested but is an area where significant [[clearcutting|clearcuts]] have occurred recently as timberland is converted to wreath brush production.

The other watersheds in Columbia contain the main stem of the Pleasant River in the northern part of town, including the Great Heath described below. The West Branch of the Pleasant River rises in two sub-watersheds in the southeastern part of Columbia and drains south toward Addison.

The portion of the watershed that has the greatest potential to affect a body of water is its direct watershed, or that part which does not first drain through upstream areas. Anything that can be transported by water will eventually reach and impact the quality of a water body. Development activities, such as house and road construction and timber harvesting, may disturb the land that drains to a lake by streams and groundwater and contribute pollutants and other substances to water bodies, degrading water quality. Activity anywhere in the watershed, even several miles away, has the potential to impact the water quality of our streams, rivers, ponds and lakes.

Threats to water quality come from point and non-point discharges. [[Point source pollution]] is discharged directly from a specific site such as a municipal sewage treatment plant or an industrial outfall pipe. There are no point source discharges within the Town of Columbia.

Non-point source pollution poses the greatest threat to water quality in Maine communities, and Columbia is no exception. The most significant contributing source comes from erosion and sedimentation as well as excessive run-off of nutrients, particularly phosphorus. In excessive quantities phosphorus acts as a fertilizer and causes algae to flourish or "bloom". Additional contributing factors include animal wastes, fertilizers, sand and salt storage, waste lagoons, faulty septic systems, roadside erosion, leaking underground storage tanks, and hazardous substances.

Identification and regulation of these sites is important to safeguard both surface and ground waters. The non-point source pollution in Columbia caused by failing septic systems, run-off from surrounding agricultural land, and aerial spraying of herbicides threatens Schoodic Lake and kettle hole ponds, the Pleasant River and the headwaters of the Harrington River (Great Marsh Stream and Dorr and Trout Brooks). A small area along the western edge of the town drains to the Narraguagus River via Schoodic Lake. Camp development and blueberry agriculture could pose a serious threat to the water quality of this cold water lake.

According to the ME-DEP Lake Water Quality Monitoring Report for Schoodic Lake provided by the PEARL spatial database, water quality monitoring data for Schoodic Lake has been collected since 1977.

During this period, five years of basic chemical information was collected, in addition to eight years of Secchi Disk Transparencies (SDT). In summary, the water quality of Schoodic Lake is considered to be average, based on measures of SDT, total phosphorus (TP), and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Schoodic Lake is low.

Schoodic Lake is a non-colored lake (average color 8 SPU) with an average SDT of 5.5&nbsp;m (18&nbsp;ft). The range of water column TP for Schoodic Lake is 4–15 parts per billion (ppb){{Vague|parts by mass, by volume, some strange and not quite accurate g/m³ hybrid?|date=March 2008}} with an average of 9 ppb, while Chla ranges from 2.1 to 4.5 ppb, with an average of 3 ppb. Recent dissolved oxygen (DO) profiles show moderate DO depletion in deep areas of the lake. The potential for TP to leave the bottom sediments and become available to algae in the water column (internal loading) is low to moderate.

Schoodic Lake is managed by the Maine Department of Inland Fish and Wildlife as both a warm water and cold-water fishery. Oxygen levels below 5 parts per million stress certain cold water fish, and a persistent loss of oxygen may eliminate or reduce habitat for sensitive cold water species. The outlet of Schoodic Brook hosts a run of rainbow smelts that are dipped by locals and provide forage for landlocked salmon.

The Natural Resources Conservation Service in Machias is administering federal USDA funds in a small watersheds program known as PL566. The program focus is the Pleasant and Narraguagus River Watersheds and they are in Phase one of a three phase process that conducts an assessment of issues and concerns in the watershed (Phase I), involves stakeholders in the creation of a management plan and response to the issues (Phase II), and seeks implementation resources (Phase III) to address watershed concerns. It is a flexible program that allows funds to be directed to municipalities and not just landowners or individual producers. Columbia could participate in this process and ensure that all available resources can be tapped in support of town goals.

Water withdrawals for irrigation of agricultural crops are of concern to some residents and there is discussion of the town regulating water withdrawals from surface waters. There are commercial production wells in the northwestern part of Columbia and surface water withdrawals also occur from Schoodic Lake, Duck Pond and Myers Pond. Surface water withdrawals in Cherryfield from Crane Pond are also of concern as these are the headwaters of the Harrington River tributaries that flow through Columbia. Concerns include the long-term impact of withdrawals of low water on Atlantic Salmon and other aquatic species such as native brook trout. The state legislature resolved in 2001, by Public Law 619 not to regulate water withdrawals in organized townships. Instead they chose to study the amounts and uses of existing water withdrawals and to develop a reporting system to gather this information. Columbia would like such studies to include the rivers within their boundaries.