Agenda 11-02-23; 4-a - Resolution Endorsing Consensus Principles II for Revised Falls Lake Rules

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�n=11 the Stage II requirements. Retrofitting existing development given site constraints with even one SCM is often not possible. Recognizing the uncertainty associated with model-based load reduction targets, Section 5(f) of the Falls Lake Rules included an adaptive management provision allowing for a re-examination of the Stage II requirements. The decade-long evaluation process by the UNRBA and the four-year study period funded by the NC Collaboratory have provided exceptional scientific information and knowledge about conditions in the lake and its watershed. Falls Lake is at risk of increasing eutrophication, but data and analyses indicate a relatively stable trophic condition. The lake currently meets its designated uses. Furthermore, nutrient reduction efforts in the watershed and changes in environmental conditions have resulted in significant reductions in nutrient loading to the lake since the baseline year of 2006. These conditions have not yet reflected significant and demonstrative reductions in chlorophyll-a in the lake. Due to the slow response of nutrient cycling in the lake and its sediments, the full implications of reduced loading over the last 17 years have not fully manifested. It is likely that these positive changes in the nutrient balance will be reflected over a much longer time given the large store of nutrients present in the lake sediments and the continued addition of nutrients from the watershed. Other watersheds in the country face similar challenges. The Chesapeake Bay Program Scientific and Technical Advisory Committee (STAC) released a Comprehensive Evaluation of System Response in May 2023. Similar to the Falls Lake watershed,the report concludes that "current efforts to reduce nutrient loads will not meet the TMDL targets" and that "estuary water quality has been slow to respond to realized nutrient and sediment reductions in many regions of the Bay." This report focuses on an estuary that drains a much larger watershed with more opportunities for implementation given the relative amount of agricultural land and urban land in the watershed. Even with additional opportunities for implementation in the Chesapeake Bay watershed, the report concludes that "additional nutrient reductions will improve water quality, but water quality criteria may be unattainable in some regions of the Bay under existing technologies" and that "the legal requirements of the Clean Water Act(the water quality goal) divert attention away from considering multiple means of improving living resources (support of aquatic life as the designated use)." As noted above, the current Falls Lake Nutrient Management Strategy is not technically,financially, or logistically feasible due to the unique characteristics of the watershed and the reservoir. A revised Nutrient Management Strategy for Falls Lake based on the science available and sound management principles is needed to protect this resource. While it is impossible to change the fundamental characteristics of this watershed and reservoir that make it eutrophic, a regulatory framework for nutrient management is essential for maintaining designated uses. The critical management objective for Falls Lake must be to mitigate impacts from existing activities in the watershed and to design and manage land use changes while continuing to maintain and improve water quality in Falls Lake. Without reasonable, balanced, and economically supportable actions, the risk of increased eutrophication, degradation of water quality, and adverse impacts to designated uses is a real possibility in the face of changing land use patterns and climatological conditions. Key Findings from Information Gathering, Monitoring, and Modeling Studies Before the comprehensive monitoring and modeling effort began, the UNRBA conducted an open and transparent planning process to ensure the requirements for a re-examination specified in the Falls Lake Rules were met. The state-approved monitoring and modeling quality assurance project plans (QAPPs) ensured the work of the UNRBA was conducted in a scientific and quality-assured manner. Since the monitoring effort started in 2014,the UNRBA has made considerable effort and investment to further the scientific understanding of the watershed and the lake. The UNRBA has ii