Modeling and Mapping

June 9, 2016

In past years, government offices had cubicles stuffed with rolled up paper maps. Another section of the office might contain stacks of work orders. Hours of time could be lost if a map or a work order was misfiled. Just finding a properly filed map or a work order in a stack was a big cost in time.

Today’s software has eliminated the paper maps and work orders and vastly streamlined the process of mapping, modeling, and tracking work orders. Now stormwater managers can have the information, maps, and records at their fingertips, either on an office computer or in the field with a mobile device.

Software has also transformed the design process. Using software, a person can see how the pieces of a stormwater system work together. You can change a culvert or retention pond size to see what the effect will be. The software allows the design to be as efficient and cost effective as possible before any dirt is dug for installation of pipes, culverts, catch basins, and retention ponds.

Another big advantage of these software packages is being able to easily generate the reports required by state and federal environmental agencies. With the information already available, the software is programmed to pull together what is needed in much less time than was once required.

But how do you choose what software to buy? What will be the most effective way of using the software? How do you figure a budget for ­training or implementation?

There are two main types of software that can be useful to the stormwater manager. Modeling software can assist with understanding of a watershed, especially one with complicated flow patterns. The visualization aspect of modeling software often makes clear the problem areas. Another use is seeing the impact of adjoining watersheds or stormwater systems, leading to regional cooperation.

This kind of software can also be used to design a system to handle different sizes of runoff volume or to choose a BMP to put in place. It’s much easier and more cost effective to model a 3-foot pipe, compared to a 4-foot pipe on your desktop than to put one choice in place and find that it is not the right size.

Another kind of software helps with mapping, recordkeeping, and sampling observations, ensuring compliance with permit requirements. As states make their requirements more stringent, stormwater managers need easier access to the information and reports that must be filed.

Here are some projects where both types of software have been used. Learning from other stormwater experts can help you choose what software is needed for your office.

Modeling Toronto
The Toronto and Region Conservation Authority (TRCA) works to ensure that watershed management principles lead to a healthy system of rivers and shorelines and sustainable communities. Six member municipalities include city of Toronto, Regional Municipality of Durham, Regional Municipality of Peel, Regional Municipality of York, Township of Adjala-Tosorontio, and the Town of Mono. TRCA’s location around several rivers and creeks and Lake Ontario leads to a need for a regional plan to keep the waters clean.

Updates for floodplain mapping used to be completed using the public domain one-dimensional (1D) HEC-RAS model developed by the US Army Corps of Engineers. Most of the floodwaters flow in well-defined valley systems along the main channel. However, according to Dilnesaw Chekol, Ph.D., water resources analyst for TRCA, there are areas where flood events send water flowing in multiple directions. To accurately define these hydraulic conditions, different software was needed for modeling.

TRCA chose DHI Software’s MIKE FLOOD software, which couples the MIKE 11 (1D) and the MIKE 21 (2D) hydraulic models. The study area was the lower reach of the Don River in Toronto, ON. The northern section has a natural channel and a well-defined valley system. But the southern part would overflow in multiple directions during a severe flood. The channel is constrained and straightened, leading to this problem. The river is adjacent to a main transportation corridor, meaning that flooding issues were even more complicated and could cause great disruption to the area.

DHI Software, located in Cambridge, ON, supplies several types of software based on MIKE FLOOD. The software can be customized for the client’s needs. The company has 50 years’ experience dealing with water issues and supplies its software to governments and contractors around the world.

TRCA wanted its model to simulate frequent storm events as well as infrequent large storms. Hurricane Hazel was the greatest storm event ever in this region, so that was at the top of the scale for planning. Combining the ID and 2D models allowed accurate predictions of the complex hydraulics in the area.

The coupled model was a big advantage for a study in this urban environment because the streams and rivers do not all have well-defined channels. Hydraulic simulations need to combine all the types of channels and the flooding possibilities. Adding stormwater infrastructure is also a big plus, even though that feature was not used for this study. Chekol says that the software lends itself well to producing clear visualizations and useful animations, as well as post-processing with GIS.

However, Chekol says that the real value is the interface, visualizations, stability, and most importantly the ability of the model to solve complex flood problems and produce accurate and defensible results.

For others who might be starting a similar project, Chekol recommends that the project be broken into sub-projects to address multiple objectives. Sometimes a small section is the best way to start.

Oregon Marketplace
In October 2015, Regency Centers began construction on the 17.8-acre Northgate Marketplace Phase II located in Medford, OR. The approximately 180,000-square-foot site will be anchored with Dick’s Sporting Goods and Field & Stream Shop, HomeGoods, and other retailers. The development will include gathering areas and plaza spaces, which will help create an enhanced shopping experience.

DOWL, a consulting business, was contracted for civil site and utility design, landscape architecture design, and stormwater analysis for the project.

The goal was to create passive vegetated stormwater treatment systems that would also add to the aesthetics of the site. Bioretention planters have been designed within the parking areas, and a water-quality/-quantity pond was incorporated into the landscape buffering to provide a natural transition from the public roadways to the shopping center. Stormwater systems have been designed to capture, convey, and treat the runoff from onsite impervious areas prior to discharging into the public storm sewer system.

According to Atalia Raskin, P.E., water resources project manager, the software chosen for the project was xpswmm Version 17.0 from XP Solutions of Portland, OR. Xpswmm combines hydraulic and hydrologic modeling software. The software is one of the best known in the industry and it has been around for 25 years. Interaction among all the elements of stormwater systems allows the user to see the proposed system and tinker with elements to reach the desired results. The accuracy of the model leads to real-life results as designed. The model can also integrate with GIS data, as well as CAD information.

Raskin says one advantage of the xpswmm software is easy import of AutoCAD pipe networks for model development. The interface is clear and easy to use, and the output reports are easily customized and quickly generated. Both storm sewer and stormwater facility sizing can be handled with one program. It is also able to integrate the conveyance system and water-quality/-quantity pond. “This is important in understanding the influence of the stormwater facility on the hydraulic grade line in the conveyance system, and can help identify and avoid future onsite flooding,” says Raskin.

Xpsmmm was chosen for its ease of use in developing the hydraulic model and generating reports, which provide the reviewing agencies the detail and accuracy they are looking for during the permitting and approval process. “This allowed us to quickly and effectively create the hydraulic model and complete our project on time and on budget, even while making adjustments to the report as the site development designed evolved,” says Raskin. “This time savings makes using xpswmm a cost-effective software when completing hydraulic analysis for commercial developments.”

Raskin recommends xpswmm for similar projects, especially when conveyance modeling needs to be integrated with stormwater treatment and facilities.

A Growing Canadian Town
Cobourg, ON, consists of 18,000 residents but is expanding rapidly. Four creeks run through the town and then into Lake Ontario. The town has faced several major floods in recent years. Water quality ranks as a high concern for the area.

The Ganaraska Region Conservation Authority (GRCA) is tasked to conserve, restore, develop, and manage the natural resources of the area. GRCA received a grant from the Ontario Ministry of the Environment to conduct floodplain mapping.

One of the big challenges was combining existing and proposed development. Many subdivisions had been built on floodplains that would not be allowed today. Those past developments had to be protected, as well as the ones that are impacted by their presence in the floodplain. Future developments that are mapped out but not yet constructed also needed to be included in the plan. Modeling storm flows must ensure that infrastructure can be put in place to mitigate not only today’s flooding risk, but also that from future development.

The town used Esri’s terrain dataset with ArcGIS 3D Analyst extension to produce a digital elevation model (DEM). Once the floodplain elevations and boundaries were known, designers could move forward to determine the BMPs needed to mitigate the risk.

Detention ponds were built to decrease stormwater flows and to collect sediment before it could enter the creeks. Using ArcGIS 3D Analyst, GRCA was able to input multiple parameters such as land availability, geographic conditions, and site-specific jurisdictional issues. The model was also used to evaluate the effectiveness of each pond before it was built.

Esri is well known to most stormwater managers and city planners for its GIS-based maps and applications. ArcGIS 3D allows a user to visualize the study area in three dimensions, as well as change criteria to see how a new development or added BMPs would change the environment and flooding possibilities. The hydraulic DEM produced by the software can be used in other applications to model for all types of storm events.

South Carolina Stormwater
About five years ago in Horry County, SC, employees were still using paper and pencil and had no standard work order management, especially for stormwater engineering and public works. The inefficiency drove them to find a digital solution. Tim Oliver, GIO assistant CIO for the county’s IT/GIS department, says the county wouldn’t look at an enterprise application without it being GIS centric: “Everything local government does is tied to the map.”

Stormwater managers felt the same. All the county departments wanted a flexible, customizable solution. They searched for a software solution and chose Cityworks, supplied by Azteca Systems Inc. of Sandy, UT.

Cityworks is a GIS-based asset management system, incorporating the GIS software that many government agencies already possess and use. Cityworks also has robust asset data management storage. Map layers can display open work orders, recent inspections, and ongoing projects, as well as other information. Reports are easily generated and information is available to managers in the office or workers in the field. Asset inventory can be easily updated. A record of maintenance can show assets that are costing more in time and money than they should, possibly pointing to a need for replacement.

The county covers more than 1,200 square miles and was experiencing rapid development. Each residential area included detention ponds. There was a need to track ditch and detention pond cleaning, log work orders completed, and keep records of easements and documents. The county also wanted a mobile application that citizens could use—a person could take a picture of a clogged drainage pipe and send it to the correct department through the website or using a smartphone.

Communication between departments has increased the usability of the software. One department might find a way to use the software to solve a problem and will pass that knowledge on to another department, which might change it slightly to fit its own needs.

Tom Garigen, head of the county’s stormwater department, says the county has now been using Cityworks for more than five years. He notes that although Cityworks is not specifically stormwater software, it has definite uses for the field. “We find it essential for reporting and tracking of labor, materials, and equipment costs.” The county also was able to provide FEMA with information needed for reimbursement of expenses after an ice storm in 2013 and flooding in October 2015. The software had the needed information and it was easily accessible, so the process was expedited without tying up a large amount of resources.

Meeting California Regulations
ITRenew of Newark, CA, provides information technology support and security for data centers. The ­company has a 7.51-acre site that is basically a building surrounded by parking lot in an industrial park; the site backs up to a dry creek. As of July 2015, the site is subject to the new, more stringent California Industrial Stormwater ­General Permit regulations. Almost every industrial facility of any type must make stormwater management maps of its site, keep monthly records, and take samples.

Melissa Ta, compliance manager of ITRenew, says the reality of the regulation means that the company has to submit and update a site map, prepare a stormwater pollution prevention plan (SWPPP), collect samples four times a year, maintain a minimum of five years of records, conduct monthly observations, implement best management practices onsite, and perform annual evaluations of the project. For many businesses, these tasks are an overwhelming prospect and they needed help to meet the requirements.

ITRenew first faced the challenge of identifying how the drain inlets on the site were connected and how and where they entered the main central pipe. Working with the city, the company was able to work out a blueprint of the piping system and know which water body was receiving the discharge. That information allowed them to specify which storm inlets would be sampling locations and where stormwater mitigation was needed.

Another challenge was determining what BMPs would be the best fit. Ta says that picking the right BMPs is an ongoing learning process. Catch basin inserts and sampling equipment have been installed.

Since October 2015, ITRenew has been using Mapistry software to manage the SWPPP, make and record monthly observations and samplings, record sample results, and keep an updated site map. Ta says the advantages of Mapistry are that it provides the entire bundle of resources to complete and submit the SWPPP to the State Water Board. She found the mapping tools useful to label sampling locations, site areas, industrial processes, drain inlets, and flow directions. This allows the map information to be easily pulled into the templates used for monthly and sampling observations. The software also stands as the recordkeeper for any audits.

Ta also asked Mapistry for recommendations for BMPs and the company gave her a list of possibilities so she could decide what would work best for the situation.

Mapistry software includes a cloud-based dashboard and mobile apps. The maps, forms, and sampling observations are specific to the permits for each state. Map layers are pre-loaded and can be customized to show SPCC (spill prevention control and countermeasures), hazardous materials plans, and locations of fire extinguishers, among other items. The layers in the mapping tool display the permit requirements, so that does not have to be added by the user.

The mobile app, of course, requires Internet connectivity to work, and an area at the back of the site has little to no service, so employees sometimes go back to pen and paper to record observations, then transfer them to the software in the office.

Ta says the software has been extremely beneficial. The purchase of the software includes the services of a program manager who can help with questions. Training and onsite consultation are available for a fee. Free educational webinars are offered to the public, and the software’s connection with NOAA (the National Oceanic and Atmospheric Administration) provides notice of any qualified storm events.

Ta says that her recommendations for anyone considering a similar software purchase are to attend as many informational webinars as possible to get a full understanding of the permit and its requirements, and to ask lots of questions of different people. “You will learn tidbits here and there that will help shape your own program. It’s a very complicated and detailed permit, so it is good to keep your program as simple as possible to allow for flexibility.” She realizes that she will have to keep learning what works and what doesn’t, and often the easiest way to see that is through software such as Mapistry.

No matter what your software needs are, you can find a match. Here are some tips from fellow stormwater experts:

  • Decide exactly what you need the software to do. If you can’t be specific, brainstorm until you have a basic framework for what you want.
  • Determine a budget.
  • Get as much training as you can, whether it is from free webinars or training from the software supplier.
  • Be ready to just try the software. You might be surprised what you find you can do.
  • If you work for a government, share information and ideas among the departments. This can drastically cut the learning curve.
  • Remember that a model or a map is only as good as the information it contains. The results from a model may not be as good as what a person can see for themselves. Models may need tweaking from a person with experience before any modeling analysis can be accurate.

Software has found its way into governmental and business offices, pushing out the wall of maps and work orders. It’s up to stormwater managers and ­employees to find the best match for their needs and then to learn to use the software in the most effective and efficient way.  

To access additional case studies and in-depth reporting, check out June edition of Stormwater.

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About the Author

Roberta Baxter

Author Roberta Baxter specializes in science and technology topics.

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Microplastics that were fragmented from larger plastics are called secondary microplastics; they are known as primary microplastics if they originate from small size produced industrial beads, care products or textile fibers.
Microplastics that were fragmented from larger plastics are called secondary microplastics; they are known as primary microplastics if they originate from small size produced industrial beads, care products or textile fibers.
Microplastics that were fragmented from larger plastics are called secondary microplastics; they are known as primary microplastics if they originate from small size produced industrial beads, care products or textile fibers.
Microplastics that were fragmented from larger plastics are called secondary microplastics; they are known as primary microplastics if they originate from small size produced industrial beads, care products or textile fibers.
Microplastics that were fragmented from larger plastics are called secondary microplastics; they are known as primary microplastics if they originate from small size produced industrial beads, care products or textile fibers.
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