Vegetated Riparian Buffers: Developing Science-based Ordinance Protection

1. Vegetated Riparian Buffers:Developing Science-based Ordinance Protection Belgrade Regional Conservation Alliance

2. Outline • What do we mean by riparian buffers? • Values of buffers-what do they do? • How wide do they need to be? • How do they work? • What are characteristics of a good buffer? • Buffer ordinances- how do we protect buffers? • Summary and recommendations

3. What do we mean by Riparian Buffers? • Vegetated transition zones between upland and aquatic ecosystems • Provide wildlife habitat • Provide nutrients and energy for aquatic systems • Protect water quality • Shading • Nutrient uptake • Pollutant removal • Stabilize shorelines • Provide flood control and protection

4. Riparian Buffer Cross-Section

5. Riparian Buffer Plantings

6. Headwater Stream Buffers

7. How Wide Should a Buffer Be?

8. Buffers and Water Quality • Settling of particulates • Potential for resuspension • Adsorption and ion exchange-surface • plants, substrate, sediment, litter • Plant uptake (temporary storage) • Microbial biodegradation • Denitrification • Soil sequestration • Predation and die off of pathogens

9. Characteristics of Runoff • Groundwater flows • Velocities very slow: 1-3 ft/day • Pollutants dissolved • Sheet flows • Velocities moderate: 1-5 ft/min • Pollutants dissolved and particulate • Concentrated flows • High velocity: in excess of 1 ft/sec • Pollutants primarily particulate

10. The Impact of Development on Storm Water Runoff natural conditions

11. The Impact of Development on Storm Water Runoff medium density development

12. Déjà Vu “There are mountains in Attica, which can now keep nothing but bees, but which were clothed, not so very long ago, with fine trees producing timber suitable for roofing the largest buildings….while the country produced boundless pasture for cattle. The annual supply of rainfall was not lost, as it is at present, through being allowed to flow over a denuded surface to the sea, but was received by the earth, in all its abundance, into her bosom where she stored it.” Plato: Dialogue of Critias 360 B.C.E

13. Stormwater Runoff • Fertilizers • Pesticides • Bacteria from pet and agricultural waste • Eroded soil • Flowing water erodes even more soil • Road salt • Oil and grease, antifreeze • Heavy metals • Grass clippings

14. (M) From: Wenger (1999)

15. From: Wenger (1999)

16. From: Wenger (1999)

18. Phosphorous Release from Particulates vs. Temperature Ref: Karr, 1977

19. Characteristics of good buffers • Dense vegetation to slow flows • Multi layer: trees, shrubs, forbs • No channels or shortcuts • Native plants • Developed root systems to encourage infiltration and microbial rhizosphere communities • Permeable soils with high organic content • Grassy edges to encourage sheet flow

20. Transpiring Recyclable Energy Efficient Stormwater System TREES

21. Role of Plants • Production of organic matter-photosynthesis • Shading and cooling (evapotranspiration) • Organic matter decays to litter layer • trickling filter, adsorption bed • burial and diagenesis-organic carbon at depth • Stabilization of sediments • Slow flows- enhance sedimentation • Epiphytic algae and bacteria • Oxidized rhizosphere • Evapotranspiration-driven transport • Bioturbation and bioirrigation

22. Deja Vu The roots of the willows do not suffer the banks of the canals to be destroyed; and the branches of the willows, nourished during their passage through the thickness of the bank and then cut low, thicken every year and make shoots continually, and so you have a bank that has life and is of one substance. -Leonardo Da Vinci (1452-1519)

24. Recommendations (Wenger, 1999) • Option 1: 100 ft + 2 ft per 1% of slope • Include all floodplain and adjacent wetlands • Impervious areas and slopes over 25% excluded • All perennial, intermittent, and ephemeral streams • Option 2: 50 ft + 2 ft per 1% of slope • All perennial, 2nd order intermittent streams • Option 3: Fixed buffer width of 100 ft • All perennial, 2nd order intermittent streams

25. Protection of Riparian Buffers • Regulations and ordinances must be scientifically defensible • Must be easily understandable and implementable • Must be enforceable • Must take into account local conditions

26. Protective Regulations:Shoreland Zoning Act 75 ft vegetated buffer from high water line Up to 40 % thinning over 10 yr period

27. Shoreland Zoning Designed for reducing the impacts of development Retains the natural forest floor

28. NJ Stream Encroachment Rules • Riparian zone regulated: • 300 ft for Category I waters • 150 ft for trout waters and T+E waters including tributaries 1 mi upstream and for acid-producing soils • 50 ft all other waters (USGS Topo or Soil Survey Maps) • Permit by rule for agriculture

29. Effective Buffer Ordinances • Provide guidelines for buffer creation and maintenance and should require: • Justification for buffer protection • Buffer boundaries to be clearly marked on local planning maps • Maintenance language that restricts vegetation and soil disturbance • Tables that illustrate buffer width adjustment by percent slope and type of stream • Direction on allowable uses and public education

30. Model Ordinances • EPA web site: • www.epa.gov/owow/nps/ordinance/buffers.htm • Contains ten different model ordinances with language for special circumstances (erodible soils etc.) • Center for Watershed Protection: • www.cwp.org/Resource_Library/Model_Ordinances/index.htm • Contains post-construction ordinances, wetlands protection ordinances

31. Typical Ordinance Content 1: Background Why buffers important 2: Intent Purpose of the ordinance 3: Definitions 4: Applications Development, mining, timber, agriculture 5: Plan Requirements Wetlands, slopes, soils, etc 6: Design Standards for Forest Buffers How wide, slopes, hazards, zones, etc

32. Typical Ordinance Content (Cont.) 7: Buffer Management and Maintenance Clearing, roads, bridges, paths, stormwater, invasive species, etc 8: Enforcement Who, penalties, etc 9: Waivers/Variances Grandfathering, variance procedures 10: Conflict with other Regulations Most stringent shall govern References

33. Summary and Recommendations • Buffers perform critical functions for Water Quality • Existing regulations (Shoreland zoning) provide some protection • Protective ordinances can provide additional protective • Must be based on science and local conditions to be effective and defensible

34. References • Mayer et al. 2005. Riparian Buffer Width, Vegetative Cover, and Nitrogen Removal Efectiveness- A Review of Current Science and Regulations. USEPA 600/R-05/118 • Wenger, 1999. A review of the scientific literature on riparian buffer width, extent, and vegetation. U. GA. March, 1999. • Karr, 1977. Impact of nearstream vegetation and stream morphology on water quality and stream biota. USEPA 600/3-77-097

35. More References

36. Questions? Belgrade Regional Conservation Alliance P.O. Box 250 Belgrade Lakes, ME 04918 (207) 495-6039 http://www.belgradelakes.org brca@belgradelakes.org