Water Quality Services

Watershed management and stormwater master planning can take on a wide range of forms depending on the project goals, specific needs in the watershed, and characteristics of the watershed. Floodplain studies and mapping are often a component of watershed management and stormwater master planning but are sometimes done independently. Likewise, hydrologic and hydraulic (H&H) stormwater modeling is typically a component of planning and mapping studies but can also be done separately to help solve a specific problem as part of the preliminary engineering phase for a design or in support of an Environmental Resource Permit. FEMA Flood Map Revision Processing is often done as part of a planning study or H&H modeling project. Finally, nutrient-loading-and reduction analyses are sometimes performed as a component of large planning studies or as standalone projects in support of Basin Management Action Plans (BMAPs) for TMDLs. Jones Edmunds takes a collective approach to these services by breaking them into smaller components. We have emphasized model-GIS integration because of its importance to cost-effectiveness.

Jones Edmunds has an outstanding history of advocacy on TMDLs for public entities. We understand the multitude of issues involved and can help direct an approach that balances protecting the natural resources, stakeholder goals, and cost-effectiveness. From assessing the science and verifying the impairment to establishing or re-establishing load reduction requirements and the most cost-effective means to achieve them, Jones Edmunds’ team of water resources professionals provide outstanding value and creative solutions for your TMDL needs.

Verifying Impairment
Given the financial implications of most TMDLs, it is important to verify that an actual impairment exists and, if it does, the extent to which it exists. It is important to get the science right. Water quality is affected by multiple processes in streams, lakes, estuaries and other water bodies—often resulting in highly variable water quality data that can be challenging to interpret. This variability is not always adequately characterized in existing water quality data sets, yet these data sets are used to determine the impairment status of a water body and also influence the level of pollutant-load reduction required in the TMDL.

We have assisted clients with active involvement in this step – leading to a TMDL being not required or a significant decrease in the pollutant reduction required. Our expertise in data analysis and water quality monitoring will help to ensure that your restoration efforts are appropriately scaled and directed at the right water bodies.

Quantifying the Required Restoration
The next important step in the process is determining the level of restoration needed to meet water quality standards. For a pollutant indicator such as fecal coliform, this is a relatively straightforward process. For standards such as Chlorophyll-a or Dissolved Oxygen, the process can be much more complex since there first needs to be a clear causal relationship established. Assuming a causal relationship can be established, a determination needs to be made on the assimilative capacity of the water body and what pollutant reduction is necessary to meet water quality standards. Assimilative capacity may be hard to determine since the available data may only cover periods of pollutant impairment. Some form of modeling is typically required to make these determinations. The modeling performed to develop a TMDL may be empirical (based on existing data) or mechanistic (process-based simulation models). In some cases both types of modeling may be used. We have valuable experience in both types of modeling related to TMDLs and have even developed a GIS-based continuous-simulation pollutant-loading model that has been used to participate in TMDLs and manage watershed planning activities in multiple watersheds with a wide range of hydrologic conditions. Jones Edmunds has also applied our modeling experience on peer reviews of existing TMDL models, resulting in changes to the TMDL.

Developing the Least-Cost Restoration Plan
Planning and implementing cost-effective pollutant-loading-reduction projects may have the greatest TMDL cost implications for a TMDL stakeholder. An often-overlooked part of this process is first obtaining proper credit for current pollutant-loading-reduction activities.

The next step in the process is to maximize the reductions that can be achieved through non-structural means. Programmatic actions and policies such as downspout disconnections and fertilizer ordinances can be several orders of magnitude more cost-effective than structural measures. Maintenance activities such as frequent catch-basin cleanouts and street vacuuming often can also be more cost-effective than structural controls. However, these types of non-structural measures are usually limited in the amount of reduction they can achieve, so it is important to understand and quantify realistic non-structural expectations to know what then must be handled by more expensive structural controls. Our experience in making these determinations, such as in Lemon Bay, Roberts Bay, Sarasota Bay, and Little Sarasota Bay watersheds, will help to lower your overall implementation costs.

The final element in the planning process is developing cost-effective structural water quality improvement projects that will achieve the remaining portion of the restoration goal. In our experience, there are two keys to this element. The first is to begin with the premise that you are trying to accomplish the lowest dollars/pound-removed load reduction instead of trying to comply with new development standards and conventional design criteria. This approach opens up a broader palette of BMPs for use and also allows them to be applied differently and more creatively. The second is to have projects at different scales. Regional BMPs are often one of the most cost-effective structural means to achieve pollutant-load-reduction goals because of the economies-of-scale involved with them. However, there may be practical limits on what can be accomplished with them due to land availability or other factors. Additionally, there may be years when an entity cannot fund a large project but would still like to demonstrate progress. For these instances, smaller-scale projects that are often retrofits involving low impact development (LID) practices are more appropriate. Our extensive experience with LID practices—including developing Florida’s first LID Design Manual that receives recognition in the Statewide stormwater permitting process—allows us to readily identify the most effective mix of retrofit opportunities and the most appropriate practices for them.

• Low-impact development design
• Water quality modeling
• Surface water monitoring
• Permitting assistance
• Sedimentation and erosion control