Code of Maine Rules
01 - DEPARTMENT OF AGRICULTURE, CONSERVATION AND FORESTRY
672 - LAND USE PLANNING COMMISSION (formerly Land Use Regulation Commission)
Chapter 10 - LAND USE DISTRICTS AND STANDARDS
APPENDICES
Appendix 672-10-A - SAMPLE DETERMINATIONS TO IDENTIFY WATER QUALITY LIMITING LAKES

Current through 2024-38, September 18, 2024

Purpose. The purpose of the following is to determine those lakes where a density of one dwelling unit per 150* feet of shoreline of the lake would increase the phosphorus concentration of the lake water by 5 parts per billion or more.

Method. The maximum change in phosphorus loading will be determined by:

(1) [DELTA]L = [DELTA]P x DA x R

Assuming 1/4 time occupancy, four people per dwelling, and a contribution of .4 x 103 grams of phosphorus per person per year to the body of water, the water quality limitation to shoreline development is:

(2) max. [DELTA]L = number of dwelling units .4 x 103 grams per year

If development was allowed to a density of 1 dwelling unit per 150 feet of shoreline, the maximum number of dwellings allowed according to shoreline length only would be:

(3) shoreline length = number of dwelling units 150 feet

If (3) is greater than (2), the lake is a water quality limiting lake;

If (2) is greater than (3), the lake is not a water quality limiting lake;

* Since the minimum shore lot frontage on major water bodies is 150 feet measured as a straight line between the points of intersection of side lot lines with the normal high water mark of the shoreline, and due to the irregularity of shoreline, the actual average shoreline measure along the normal high water mark for such lot is estimated to be 150 feet.

Sample 1

Madawaska Lake, Aroostook County

Calculations:

(1) Maximum [DELTA]L = 20.7 x 104 grams per year.

(2) Number of dwelling units allowed based on water quality limitations = 518 dwelling units.

(3) Number of dwelling units allowed based on shoreline length = 360 dwelling units.

Result: Madawaska Lake is not a water quality limiting lake.

Sample 2

Tomah Lake, Washington County

Calculations:

(1) Maximum [DELTA]L = 5.4 x 103 grams per year.

(2) Number of dwelling units allowed based on water quality limitations = 14 dwelling units.

(3) Number of dwelling units allowed based on shoreline length = 47 dwelling units.

Result: Tomah Lake is a water quality limiting lake.