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Posts Tagged ‘ecosystem services’

Riparian and Wetland Buffers for Water Quality Protection: A Review of Stormwater Journal’s “Literature Review”

November 24th, 2009

Last week we alerted you to the release of the November/Decemberedition of Stormwater Magazine, including a reference to an article entitled “Riparian and Wetland Buffers for Water-Quality Protection: A Review of Current Literature,” the full text of which is available here.

Upon a more careful reading, we have some questions and concerns about the piece.

First, their buffer recommendations substantively appear to us to be weak.  Authors seem to recommend a buffer width of 50 feet:

For streambank stability, temperature control, minimization of direct impacts, and pollutant removal capacities, substantial benefits are achieved within the first 50 feet of vegetated buffer width.

In contrast, the Pennsylvania Campaign for Clean Water recommends a buffer width which varies from 100 feet total for all streams, to 150 feet for first order streams and impaired streams, to 300 ft for Special Protection (EV and HQ) streams (roughly comparable to New Jersey state regulations). PADEP is recommending 150 feet for EV streams in its Draft Chapter 102 regulations.

Secondly, authors draw their conclusions based on extremely dated references — many from the 1970’s, ’80’s, and ’90’s.  References also seem to omit or ignore so many other commonly accepted riparian buffer authorities and respected sources (Correll, Lowrance, Peterjohn, Sweeney, Welsch, US Forest Service, Chesapeake Bay Foundation, and so many others), omitting some important recent work which is the advertised purpose of this article (viz., “…A Review of Current Literature”)!  We would expect attention to both recently published journal articles with new research findings as well as the more recently published manuals and guidance documents.  If this is a summary of review of 137 different sources, it seems to be an extremely selective summary.

The authors ostensibly focus only on water quality — which is a fine and very important objective.  However, before final buffer width recommendations can be made (by anyone), there needs to be acknowledged the reality that riparian buffers provide a much longer list of “ecosystem services” which should be integrated into buffer width recommendation decisionmaking, management, regulation.

A related concern is what is being regulated and how it is being regulated within the riparian buffer zone - a dimension of issues which is not really addressed by the authors here either.  In any case, the article, we believe, needs to acknowledge that buffer width recommendations should integrate all of these more complex issues - before rushing to a 50-foot buffer width judgment which it seems to want to do.

In addition, the authors seem not to understand some basic Pennsylvania context and government form elements – despite the fact that the article uses Southeastern Pennsylvania references quite liberally (which would seem to imply specialized knowledge and understanding of applicability in a Pennsylvania context). Consider the following statements made in the article:

Wetland and riparian buffer widths are instead decided at a county or township level.

When does the county level enter into this process?

Local environmental approvals that may require riparian and wetland buffers may include Sediment Erosion and Sediment Control Plans, County Grading Permits, and Nontidal/Tidal Wetland Permits.

The above terminology is not accurate.  And what does County Grading Permit mean?

In the absence of state-level rules, buffer widths are determined on the county and township jurisdictional level.

Where are counties determining buffer widths?

Critical elements of riparian buffer management are being ignored in this article.  And what is being included seems to be inaccurate - at least in some cases.  There is no discussion of PADEP’s Draft Chapter 102 regulations, which are so enormously important at the moment, and proposed riparian buffer language or the riparian buffer recommendations in PADEP’s Stormwater BMP Manual (2006) or other important “milestones” of riparian buffer management or lack of management in Pennsylvania.

In sum, we are concerned that this respected national technical journal would present this article as a summary of the science with special relevance to Pennsylvania municipalities.   We have been told that a presentation similar to this was recently made by ENTRIX authors at a Pennsylvania Builders Association conference.  If there is a point of view to this piece, Stormwater Magazine should have made this clear and not presented the article as objective science and as “…A Review of Current Literature.”

“…A Selective Review” might ring a little more true.

What do you think?

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Maintenance of Stormwater BMPs, Stream Restoration, Riparian Buffers, and Templates for Rain Garden Designs

November 16th, 2009

Stormwater BMP Maintenance Practices

Regular maintenance of stormwater facilities is necessary to save time and expense in the long term, and to ensure that the facilities are working as designed.  Maintenance programs for various stormwater management facilities and products are discussed in this article by William Atkinson in the current issue of the Stormwater Journal.  Products that are discussed include: StormFilter; Stormceptor; HydroKleen; Drain Guard; and cleaning equipment. Read the full article here

Refer also to Chapter 6 of the Stormwater BMP Manual for maintenance considerations for Structural BMPs. You can download a pdf of the complete text of Chapter 6 here.

Challenges of Stream Restoration as a Stormwater Management Tool

The first article of this series dealt with stream restoration as a valuable watershed management practice. The second article discussed construction issues. This final article combines these perspectives and ties them together through a lessons-learned perspective. Read the full article here

Riparian and Wetland Buffers for Water Quality Protection

A compelling review of 137 published scientific papers written over the last 40 years on riparian and wetland buffer widths, and on the subject of providing “ecosystem services” such as: temperature control; streambank stability and sediment control; minimization of direct human impact; removal of total suspended solids; maintaining surface water supply and quality; nitrogen removal; phosphorus removal; removal of pesticides; removal of bacteria; and removal of metals.   The authors conclude that vegetated buffers “provide substantial benefits for protecting and enhancing water quality. For streambank stability, temperature control, minimizing degradation from direct impacts, and pollutant removal capacities, substantial benefits are achieved within the first 50 feet of vegetated buffer width. Marginal increases in benefits may accrue when buffer widths are increased beyond 50 feet”.  Read the full article here

The PA Stormwater BMP Manual also provides data on ecosystem services.  Appendix A for Pollutant Event Mean Concentrations by Land Cover and BMP Pollutant Removal Efficiencies. Download a pdf of Appendix A here.

Rain Garden Design Templates from the Low Impact Development Center

Looking for planting plans for rain gardens in the Piedmont or Mountain regions of Pennsylvania?  The Low Impact Development Center provides dozens of Rain Garden Design Templates for a range of conditions that can be used “as is”, or modified to suit specific needs.  The designs are colorfully  illustrated and can be found here.

Homeowners and others can also find a step-by-step guide to design, build, plant and maintain a rain garden. Download a pdf  How-To Manual for Homeowners here .

Also, see also Appendix B of the PA Stormwater BMP Manual for a list of plant species native to Pennsylvania that are suitable for use in any number of BMPs.

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