Long Lake is a 408-acre recreational development lake located that head if it’s watershed area, with no surface water inputs, such as a river or a stream. Long Lake is feed primarily be stormwater runoff and groundwater interactions. It a narrow, deep lake with a maximum depth of 61 feet and with 37% of the lake surface area is classified at littoral. Though a small lake relative to others which attract a large clientele, its elongated shape gives it a shoreline length that is exceeded in the District only by Big Detroit and Melissa; and only Melissa has more residential structures along its shores.
Nutrient and water clarity summer averages show that Long Lake has good water quality with annual phosphorus level ranging from 11 ppb to 16 ppb and water clarity between 12 and 19 feet. 10-year summer mean for phosphorus and clarity is 12ppb and 14.5 feet, respectively.
Long Lake is known for its abundance of Northern Pike and Bluegill. The 2016 assessment showed Pike catches were higher than the lakes average and higher than other ecologically similar lakes. While there are no special regulations for Long Lake, anglers are encourage to release Northern Pike over 24 inches. Since 2001, a Walleye stocking research study has been underway to attempt to determine the best stocking method for a given lake type, despite the efforts, Walleye abundance has continued to decline.
Long Lake outlets via Joy Creek to St. Clair Lake, a lake impaired for excessive nutrients.
Long is a deep lake, and much of its shoreline slopes steeply towards the lake with nearly 37% (11,690 feet) of the shoreline length containing a steep slope (within the 75’ structure setback requirements). The natural shoreline has been greatly modified, and based upon District shoreline monitoring is continuing at a rapid pace, including installation or rip-rap, sand blankets, and vegetation removal. Of the 183 parcels surveyed in 2010, 30 contained a retaining wall within the shore impact zone. 96 of parcel (52%) were recorded as having moderately to greatly altered shorelines, including 83 with rip-rap shorelines and 60 with beach sand blankets. 87 parcels (47%) of the parcels remained in a natural or minimally altered condition.
The City of Detroit Lakes annexation of Long Lake has provided water and sewer to the east and south sides of the lake with services on the north to be completed in the next few years. It is still unknown when City utilities will be connected on the west side of the lake. It is likely that improved water quality
In the past 20 years, several resorts have been converted to large residential lots and have all been connected to City water and sewer. One RV campground still exists on the northwest side of the lake and it is likely that it too will eventually be subdivided. The City of Detroit Lakes owns Long Lake Park which contains over 2,200 feet of shoreline, located on the east side of the lake that, except for the public access, will remain in its natural condition. Along the west side of the lake, another parcel, owned by Concordia College, will also remain in an unaltered condition that will protect over 2000 feet of shoreline.
In 2003, a water control structure was installed on a wetland outlet on the north side of the lake, allowing the wetland to serve and a water detention area significantly reducing nutrient loading from the wetland. This project drastically reduced localized nuisance algal blooms in the north side of the Lake and caused in increase in mean summer water clarity by nearly 2 feet.