This pamphlet is used in concert with a spreadsheet inventory to identify entities in the Potomac basin that either directly or indirectly affect the realization of the Potomac Basin Comprehensive Water Resource Plan’s vision for the basin. It also summarizes the roles, responsibilities, and areas of authority of those entities to inform and integrate future comprehensive planning and implementation activities.
An Inventory of Potomac Basin Entities with a Role in Sustainable Water Resources Management Archives
This report describes activities conducted during the 2020 drought exercise. The exercise was virtual, and took place on Monday, Tuesday, and Wednesday, November 16-18, from 7:30 AM to 4:00 PM.
Communications during the exercise were via telephone, email, and Microsoft Teams Meeting, and all
operations were “simulated.” Twice daily email reports were sent out to stakeholders reporting on current flow and demand conditions and on simulated operations. The exercise included two special events:
- An actual test release from Little Seneca Reservoir, which was conducted over an approximately
12-hour period, beginning at 10:00 AM on Tuesday, November 17.
- A webinar by Hazen & Sawyer on the use of the Potomac OASIS model to provide probabilistic
information on future streamflows and reservoir storage levels. A PDF of the webinar on forecast informed reservoir operations is available.
Learn more about previous drought exercises and the ICPRB’s Section for Cooperative Water Supply Operations on the Potomac on the Drought Monitoring and Operations page.
Every five years since 1990, ICPRB’s Section for Cooperative Water Supply Operations on the Potomac (CO-OP) has conducted a water demand and resource availability forecast for the Washington, D.C., metropolitan area. These studies assess whether or not the current water supply system will be able to meet the needs of the region 20 or more years in the future.
Learn more about these reports on the CO-OP Long-Term Planning page.
Human uses of land and water are directly linked and must, therefore, be managed with each other in mind. This paper puts forward an approach for integrating sustainable water resource management into local land use decision-making in the Potomac basin. The approach includes developing a clear understanding of the current regulatory, programmatic, and financial approaches to land use management; identifying opportunities from innovation; and developing a flexible, stakeholder-based framework for moving forward. Four opportunities for innovation were identified in the Potomac basin utilizing this approach, including enhancing coordination and access to information, promoting incentives to achieve desired outcomes, encouraging and promoting innovation, and integrating programs to achieve multiple objectives. The successful integration of land and water decision-making requires a sustained, long-term commitment to improvement rather than a one-time fix mentality. Initial steps for implementation include identifying and engaging diverse partners, as well as establishing channels for information dissemination. The lessons learned from this work may prove valuable to decision-makers in other regions to holistically manage diverse land and water resources.
The article was published in Water 2020, 12(8), 2282; https://doi.org/10.3390/w12082282.
Aspects of phytoplankton community structure (e.g., taxonomic composition, biomass) and function (e.g., light adaptation, net oxygen production, exudation) can be inferred with a binning method that uses water transparency (Secchi depth), dissolved inorganic nitrogen, and ortho-phosphate to classify phytoplankton habitat conditions in the surface mixed layer. The method creates six habitat categories, forming a disturbance scale from turbid, nutrient-enriched waters (“degraded”) to clear waters with bloom-limiting nutrient concentrations (“reference”). Across this disturbance scale, estuarine phytoplankton exhibit strong differences in chlorophyll a, count-based biomass, trophic mode, average cell size, photopigment cell content, taxonomic dominance, and the frequency of algal blooms. Differences in ambient dissolved oxygen and dissolved organic carbon are also observed. Two alternate states are apparent, separated primarily by water transparency, or clarity.Water transparency determines cellular light-adaptation and the potential for photosynthesis and growth; nutrient concentrations determine how much of that potential can be realized if and when light becomes available. In Chesapeake Bay, Secchi depth thresholds separating the two states are 0.7–0.9 m in shallow, well-mixed, low salinity waters and 1.2–2.1 m in deeper, stratified, higher salinity waters. The water quality binning method offers a conceptual framework that can be used to infer the overall state of a phytoplankton population more accurately than chlorophyll a alone.
The report was published in the July 2018 edition of the Journal of Water.
The report was published in the April 2018 edition of the Journal of Remote Sensing.
Very small amounts of impervious cover can impact streamflows. In the Potomac basin, for example, significant streamflow alteration associated with watershed impervious cover >0.5%–2.0% have been found. Since these impacts were found with considerably lower amounts of impervious cover than previously documented in the literature, typically 10%–20%, this study evaluated whether certain watershed characteristics (e.g., watershed area, karst geology, precipitation, soil characteristics, physiographic province, and slope) make a stream reach more susceptible to the impacts of impervious cover than others. The results of this study indicate there are differences in streamflow sensitivity to impervious cover given certain landscape characteristics. The relationships of watershed characteristics with streamflow alteration in flashiness, high flow duration, and low pulse duration were evaluated. Flashiness alteration was positively correlated with impervious cover and influenced by watershed slope and area. High flow duration alteration was negatively correlated with impervious cover and influenced by mean annual precipitation and slope. Low pulse duration was poorly correlated with the watershed characteristics under consideration. These differences may assist in land management efforts and heighten awareness of the environmental impacts of impervious cover.
The full article was published in the Journal of the American Water Resources Association, 54(6), 1169-1374, and is available at https://doi.org/10.1111/1752-1688.12681.