Putting the LID on Stormwater Runoff

The following post is provided by guest blogger Thomas Powers, P.E., LEED AP, CFM, CPESC, A Project Manager with Wight & Company in Chicago Illinois and former colleague of The Inlet’s Carolyn Howard.

Thomas Powers, PE, LEED AP, CFM, CPESC

How many gallons of rain do you think falls each year on just one acre of land in Norfolk, Va.? Ten thousand? One hundred thousand?

Would you believe more than one million? Unfortunately, most of that water isn’t absorbed by the land and instead becomes stormwater runoff, carrying debris, chemicals, sediment or other pollutants. The U.S. Environmental Protection Agency (EPA) ranks urban runoff and storm-sewer discharges as the fourth most prevalent source of impairment of our lakes, streams and rivers.

The current best practices in stormwater management is called low impact development (LID), which refers to a comprehensive land planning and engineering design approach that emphasizes conservation and the use of on-site natural features to protect water quality. According to the nonprofit Low Impact Development Center, its goal is to “maintain and enhance the predevelopment hydrologic regime of urban and developing watersheds while allowing for development or infrastructure rehabilitation.”

LID strategies typically focus on reducing the quantity of stormwater runoff while improving its quality. This often requires creating a multistep “treatment train” at its source and as the runoff flows through the site and into retention areas or downstream conveyance systems. At Wight’s headquarters, for example, stormwater becomes progressively cleaner as it moves from parking lot bioswales through filtration trenches, across a restored prairie and into a naturalized detention basin.

Whenever possible, stormwater systems should follow nature’s lead and manage rain where it falls. Such solutions usually involve the use of many distributed, small-scale systems that infiltrate, filter, store, evaporate and detain runoff. In contrast to traditional stormwater practices, LID focuses on treating smaller and more frequent storm events through various cost effective features in upland areas of the watershed.

The amount of rainfall expected at the site will be a critical factor in LID strategy and design. Typically, the goal is to be able to treat 90 or 95 percent of historical storms. Another common design objective is to treat a certain depth of stormwater runoff. For example, the goal might be to treat one inch of runoff for new sites and a half-inch for redeveloped sites.

One of the most effective stormwater runoff strategies is “disconnection,” which decouples roof downspouts, roadways and other impervious areas from stormwater conveyance systems. This allows runoff to be collected and managed on-site or dispersed into the landscape. A LID best practice is to daylight roof downspouts at grade, preferably to a rain garden or bioretention area. Pavements should also sheet drain into bioswales or rain gardens.

Stormwater management best practices can be integrated into all types of buildings and sites. More information about LID can be found in this recent article in Building Design + Construction.

Funding Stormwater Improvements is a Real(ly Big) Issue for Virginia Localities

EPA’s mandate to clean up the Chesapeake Bay is real – and so are the costs. York County has projected necessary expenditures of over $94M over the next 14 years to meet the requirements. How does a community generate an average of $6.7M per year to pay for stormwater improvements? Should it increase property taxes? Taxes are deducible from taxable income. Would this tax be equivalent to the “service” for stormwater? Fees however are not deductible, but equivalent to the “service” provided (if based on impervious area.) This can be costly to large employers, commercial developments and property managers. It is this delecate balancing act among fairness, potential economic and socio impacts, and the EPA mandate that is a struggle for many communities like York County.

Read more about the considerations and discussions that the York County  Board of Supervisors is having to address Chesapeake Bay TMDL stormwater improvements within the contraints of reduced projections. http://wydaily.com/local-news/8331-york-supervisors-consider-a-tax-or-fee-to-fund-94m-chesapeake-bay-cleanup.html

Virginia Beach’s Lynnhaven River – Progress In the Making

Reducing the discharge of pollutants  to our waterways does result in a revitalization of the associated ecosystems.  That progress can seem slow; however, since the pollutants were released over several decades the cleanup will likely require a similar timeframe.  Implementation of the Chesapeake Bay TMDL will address the release of nitrates, phosphorous and sediment to the Bay from both point and nonpoint sources.  The following article discusses the Lynnhaven River and notes that visible progress can be made in less than a decade. 

Compliance with the Bay TMDL will present difficult choices and potential for increased expenditures.   When compliance results in visible progress at the scale of the Bay and elsewhere throughout Virginia, similar to that seen locally on the Lynnhaven River, then the cost/benefit will become more palatable.  The complexity of the Bay ecosystem and the uncertainties associated with the model used to evaluate the health of the Bay and the progress of its cleanup however may not translate quickly into such visible improvements that the Lynnhaven River has seen over nearly a decade, Without continued, visible improvement to the Bay and other waterways, the challenges will remain difficult.

http://hamptonroads.com/2012/01/lynnhavens-friends-celebrate-progress-dig-do-more

Chesapeake Bay Cleanup, EPA and Virginia Localities – Still Many Challenges

Virginia’s local governments, through the Planning District Commissions (PDCs), are in the process of providing information to DCR for the Phase II Watershed Implementation Plan for the Chesapeake Bay TMDL by the February 1, 2012 deadline.  The information includes a review of the modeling data used to evaluate cleanup of the Bay, an inventory of BMPs currently in place, and additional BMPs, strategies and resources needed to meet the 2025 level of implementation (60% reductions) required by the TMDL.

The following article outlines the concerns facing Gloucester County as well as many other local governments including potential increased federal regulation if cleanup progress is not sufficient, reliance on the modeling results to make that determination, and the impact of wildlife on potential progress.  Given the continued struggling economy, local governments will likely have difficulty finding the resources, both monetary and personnel, to meet the required reductions.

http://www.dailypress.com/news/gloucester-county/dp-tsq-mid-gloucester-tmdls-0126-20120126,0,3520340.story

VT Stormwater Challenges Are Not Unlike VA Stormwater Challenges

As a “Bay State”, Virginia is somewhat unique in the challenges that we face related to stormwater management. The watershed where we live and preservation of the Chesapeake Bay are a critical component of our daily lives and our future. Virginia is one of six (6) states (in addition to Delaware, Maryland, New York, Pennsylvania, and West Virginia) whose area comprises the more than 64,000 square miles of the Chesapeake Bay Watershed. Assessing, planning, funding and implementing appropriate programs for Virginia has been something that legisalators, professionals, activists and the general public have been debating for years. And in the current economy as our General Assembly prepares to convene it 2012 Session, the debate will continue.

The interview which follows highlights many of the same challenges that states outside of the Chesapeake Bay have with stormwater management and the Clean Water Act – namely that funding stormwater programs and wastewater infrastructure improvements are not always popular, there is no “silver bullet” or one-size-fits-all solution, and the immense size of the challenge can sometimes cause a paralysis to respond.

The following link contains an interview published in the Burlington (Vermont) Free Press with James Ehlers, Executive Director of Lake Champlain International and a state representative on the New England Interstate Water Pollution Control Commission. http://www.burlingtonfreepress.com/article/20120108/GREEN01/201080309

How Will Virginia Stormwater TMDL’s Affect Virginia Colleges and Universities?

The Virginia TMDL implementation process is moving ahead. Planning District Commissions have forwarded requests to municipalities for data to be submitted by February, 2012, but state Colleges and Universities may not be fully included in this process. Often municipalities may submitt land cover data and BMP data on behalf of the institution without consultation or submit data without including the land area of these campuses. Either approach can leave the institution unrepresented in the process and may result in increased TMDL reduction allocations.

The following is a summary of recent conversation with DCR on this topic:

• If a College or University has an MS4 permit, the institution will report compliance with TMDL directly to DCR.
• DCR is committed in concept to TMDL reductions as outlined in the Phase 1 Watershed Implementation Plan ( WIP 1)
• DCR should have actual reduction targets by early 2012., but will be close to WIP 1 targets as follows:
• 9% reduction – nitrogen
• 16% reduction – phosphorous
• 20% reduction – sediment
• TMDL reductions will be accordance with the following schedule:
• 2013-18 5% of total required reduction
• 2018-23 further 35% reduction (40% cumulative of total required reduction)
• 2023-28 further 65% reduction (100% cumulative of total required reduction)

(Note: timing of implementation is inconsistent with the TMDL.)

• Existing BMPs constructed in 2006 or earlier do not count toward TMDL reduction credit as they have already been factored into the model.
• Colleges and Universities will also need to comply with local TMDLs due to impaired waters in addition to the statewide TMDLs.

While this is the latest information, this process is changing almost daily as DCR works with EPA and stakeholders. Stay connected to the Inlet.

Looking for a Way to Help Virginia and the Bay? (and Perhaps Win $15,000)

Earlier in November, the Friends of the Rappahannock (FOR), The James River Association (JRA), and the Potomac Conservancy announced a competition to challenge teams of development professionals to demonstrate cost-effective approaches to replicating pre-development hydrology on several development sites across the state.  TheVirginia Low Impact Design Competition is being organized by FOR, JRA and the Potomac Conservancy and is funded by a grant from the National Fish and Wildlife Foundation.  Additional organizational partners of the Virginia LID Competition are the Virginia Section of the American Society of Civil Engineers (ASCE), Environment Virginia, and Virginia Lakes and Watersheds. First-place awards of $15,000 will be given for each of three design areas are open for competition: suburban, mixed-use development; urban redevelopment; and green roadways.  The deadline for submitting entries is February 17, 2012.  Announcement of finalists will take place at the Virginia Lakes and Watersheds Association’s annual conference in March, and the winners will be announced at the Environment Virginia Symposium in Lexington, Virginia in April.  More information: is available at http://www.virginialidcomp.org/index.html

Additional Stormwater Discussions on the Web

There are many individuals, organizations and companies that sponsor and contribute towards the online stormwater discussions not just in Virginia, but throughout the country. The Inlet was established to help sort through the pages upon pages and numerous forums out there. When we come across sources of news and information that demonstrate practical value to our readers or perspectives that push the thought process, we are pleased to introduce others to this information that we ourselves appreciate.

Here is a new blog which has caught our attention on multiple occasions in recent days. http://www.contech-cpi.com/Stormwater-Blog.aspx is produced by Contech - a national manufacturer of civil engineering site products for drainage, erosion control, retaining wall, sanitary, soil stabilization and stormwater solutions.

Click the link to read more about “The Economics of Stormwater Re-Use”, “Why We Need a National BMP Evaluation Program” and others.

Lynchburg Tables Fee, Approves Concept of a Stormwater Utility

Members of City Council (left to right, front) are Ceasor T. Johnson, M.RE., D.D., Ward II Representative; Joan F. Foster, At Large Representative; Michael A. Gillette, Ph.D. Ward I Representative; (2nd row left to right) J. Randolph (Randy) Nelson, At Large Representative; Turner Perrow, Jr., Ward IV Representative; Jeff S. Helgeson, MSFS, Ward III Representative; and Hunsdon "H" Cary, III, At Large Representative.

I may be beginning to sound like a broken record, but stormwater management is here to stay and the regulations keep coming to prove it!  How are municipalities going to afford to meet the requirements of the new (and future) laws and regulations?  Increase taxes or impose a fee? Pay through the general fund or a separate utility? Like Lynchburg, many communities, particularly the MS4 permit communities, have already begun the dialogue to implement a stormwater utility fee. These decisions are certainly not easy, and localities are cautious to properly assess and enact any new fees to constituents in these tough economic times.

For more information, read the full story from the Lynchburg News & Advance:
http://www2.newsadvance.com/news/2011/oct/25/lynchburg-city-council-tables-contentious-storm-wa-ar-1410517/

Virginia Maintains that EPA’s Computer Model Still Has Flaws

The Commonwealth of Virginia is only one of many that contend that the computer model, or simulation, that the federal Environmental Protection Agency uses to guide the six-state bay cleanup has problems which make it difficult to accurately calculate exactly what individual localities need to do in order to meet the overall goal. Recently, the Richmond Times-Dispatch published a story which details some of the confusion citing the example of Charles City County who went from meeting 52% of sediment control requirements this summer to having a surplus capacity allowing an increase in sediment load of 406% in its latest update.

The article illustrates the uncertainties involved with the allocations established in the Bay TMDL, and the constraints due to the limited data.  Although measures are needed to improve water quality in the Bay, finding a fair way to allocate pollutant loads, among states, local governments, non-point source and point source dischargers is a difficult challenge with economic consequences for all involved

http://www2.timesdispatch.com/news/chesapeake-bay-news/2011/oct/31/2/tdmain01-pollution-model-for-bay-hit-ar-1422615/#fbcomments