Chapter 587 A-C Summary

Prepared for Ground Water Workgroup Meeting
March 10, 2006
by David Courtemanch, Maine DEP

Highlights of Water Flow / Water Level Rulemaking

§470-H. Water Use Standards, rules

  • Maintain instream flows and lake levels protective of aquatic life and other uses
  • Designate watersheds most at risk
  • Based on natural variation of flow and water level
  • Variance {from a natural flow regime} allowed if use still protective of water quality within that classification

Rule Design

  • Provide consistent policy and process, support planning and dependable source development
  • Process to maintain minimum seasonal flows and water levels protective of aquatic life
  • Three rules based on water classification (AA, A/B/C, GPA)
  • Six 'seasons' defined (rivers and streams); two seasons (lakes)
  • Empirical and computational methods to determine target flows to be maintained.
  • Lakes differentiated by type of outlet.

Rules define a process to establish flows and levels for a waterbody.

  • Certain conditions/activities excepted:
    • Public emergency use (fire)
    • Return flows
    • Tidal freshwaters, unclassified waters (storage ponds)
    • Hydropower (determined by 401 certification; MWDCA)
  • Flows/water levels established in existing permits, orders, etc remain in effect for term of the agreement.
  • Standard alteration may be used.
  • Site-specific flows/water levels may be established through a water flow/level plan.
  • Variance for public water supplies to allow continued use of present supply and recognize need to maintain continuous supply during drought conditions.
  • Rules provide 5-year implementation period to allow existing agriculture and public water supply users to comply. Extensions allowed.
  • Identify "waters most at risk" for planning purposes but does not establish any separate standard for these waters.

Rules do not:

  • Prohibit all withdrawal from any waterbody.
  • Allocate water.
  • Confer any legal water rights.

Effects on groundwater use:

  • The purpose of these rules is to maintain surface water conditions that protect all designated uses. The rules concern groundwater use only indirectly, as it may affect surface water flows or water levels. Extraction in close proximity to surface waters can affect flows and water levels and the activity must be conducted in a manner that will protect the established minimum seasonal flows or water levels.
  • Reporting of groundwater extraction (required in § 470-B) is only for sources within 500 feet of a surface water and in amounts that exceed threshold volumes, the presumption being that sources outside of that boundary or in lesser amounts have no measurable effect on surface water conditions.
  • Maintenance of surface water flows and water levels need to be considered in future siting of extraction wells.

Last updated on April 12, 2006