Checklist of Best Practices to Identify Suitable Receiving Waters
The following is a checklist of local government actions to support the WRE requirement to identify suitable receiving waters given expected water resource impacts from proposed land use plans:
❏ WQSs: When planning growth and development, local jurisdictions should first identify the WQSs in those planning areas to ensure WQSs will continue to be met as the land use plan is implemented, i.e., post development.
❏ Consult Maryland’s map of designated uses HERE and enter the location of planned development in the search bar. Then click on the nearest stream or waterbody, which will bring up a blue box that you can scroll through to identify the water’s Use Class.
❏ Once you have identified the applicable designated use(s) in your planned growth area, proceed to these websites HERE and HERE to reference in the WRE the applicable water quality that must be attained in your planned growth area.
❏ Water Quality Monitoring and Assessment: Local governments should identify the assessment status of their waters where new growth and development is being planned. This will help jurisdictions understand whether their development plans fall in watersheds targeted for restoration or protection where there are different CWA processes and authorities, as well as where water quality trends are improving or declining.
❏ Consult the Water Quality Assessments and TMDLs HERE to determine the water quality status of the watershed in which your planned growth and development will be occurring.
❏ Water Quality Restoration Planning Process: Per above and where planned growth is occurring in TMDL or impaired watersheds, local jurisdictions should conduct a pollution risk assessment to estimate any increased stormwater, septic and wastewater pollution loads with proposed land use changes. Upon request, MDE’s TMDL program can assist with this assessment by using existing modeling tools, established pollution loading factors, and/or other science-based methods. The WRE should summarize the results of this assessment and describe how planned growth and development will be consistent with capacity management planning, TMDL and WQS attainment. Performing such an assessment in the WRE will help avoid situations where MDE and local delegated authorities are required to develop special permit conditions to restore water quality that delay or restrict development projects late in the process when significant time and money have already been invested.
❏ To ensure that growth is not an obstacle to achieving a local TMDL, all local governments should track load reductions occurring within the agriculture, wastewater, stormwater (both Municipal Separate Storm Sewer Systems (MS4s) and non-MS4s) and septic system sectors. The WRE should include a strategy for achieving this objective.
❏ Water Quality Protection Process: As a first line of protection, local governments should seek to first avoid new discharges to high quality waters by planning new growth and development outside of high quality watersheds or if growth is needed, redeveloping existing developed areas in the watershed using lower impact development practices than what currently exists.
❏ Maps of Maryland’s high quality (Tier II) waters and stronghold watersheds are available HERE and HERE, respectively. Drinking source water protection areas for both surface and groundwater sources can be found within MDE Water Supply Program’s Source Water Assessments, which can be found HERE. Also, the Maryland Coldwater Resources Mapping Tool is available HERE. For additional high quality waters and information, see the Water Quality Protection Process section.
❏ Where new growth and development cannot be avoided in high quality watersheds, the WRE should ensure new stormwater and wastewater (WWTP and septic) impacts are minimized as much as possible. The WRE should include strategies for identifying and ensuring implementation of applicable pollution minimization techniques. Also, the WRE should include strategies for identifying and ensuring implementation of a sufficient number of offsets for watershed impervious surface and nutrient load increases to mitigate the impacts associated with any new development in high quality watersheds.
❏ Water Quality Implementation Process: Local governments have authority for local land use planning decisions while MDE has authority for protecting and restoring water resources. Due to the fact that these land use decisions have a profound impact on water quality, it is critical that local planners consider water quality impacts early in the planning process to avoid inconsistencies with MDE’s authority for water quality restoration and protection.
❏ Due to TMDL model uncertainty, MDE recommends that local jurisdictions go above and beyond the minimum requirements for SWM on new development, Best Management Practice (BMP) implementation for water quality restoration, and WWTP optimization. As a best practice, the WRE should include strategies for ensuring this higher level of water quality restoration and protection.
❏ Flood Management Process: Within the WRE, jurisdictions should identify recurrent flooding areas in local watersheds and carefully evaluate whether climate change and planned development will exacerbate those conditions; if so, changes to the land use plan or other measures should occur. The WRE should include recommendations for quantity management requirements in those areas, including over management or retrofitting in some areas if flooding problems are severe.
❏ The WRE should determine and maintain the capacity of the stormwater system to convey runoff as growth continues. This includes identifying known and potential future flooding areas; identifying the cause of the flooding (floodplain encroachment, conveyance system capacity); and identifying constraints and possible solutions, which could include upgrading a conveyance system, developing a flood warning system, repetitive loss acquisitions, etc. to ensure that planned growth can be safely accommodated.
❏ The WRE should identify areas above and below drinking water reservoir dams and other high, significant, and low hazard dams, and should consider restrictions in these areas regarding new development unless dam safety storm capacity issues are adequate or expected to be addressed as part of a development project.
❏ The WRE should include or reference watershed management plans, hazard mitigation plans and recommend implementation of the flood control strategies from those plans. The WRE should include a recommendation that all growth strategies should be consistent with comprehensive watershed plans, studies, or capital projects implemented pursuant to Maryland’s Comprehensive Flood Management Grant Program.
