Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Draft Public Meeting No 3 Final Alts 10 03 06 Craig Edits

259 views

Published on

Published in: Technology
  • Be the first to comment

  • Be the first to like this

Draft Public Meeting No 3 Final Alts 10 03 06 Craig Edits

  1. 1. New Meadows Lake Tidal Restoration Feasibility Study October 3, 2006 Final Public Meeting Sponsored by: With funding provided by:
  2. 2. <ul><li>Study Goal & Objectives To develop and evaluate the feasibility of technical alternatives for improving water quality and enhancing ecological resources in New Meadows Lake through increased tidal exchange. </li></ul><ul><li>Public Involvement </li></ul><ul><li>A key component of the study process and any ultimate decision-making process. </li></ul><ul><li>Tonight is the final public forum held during the study. </li></ul><ul><li>The first public forum was held on June 27, 2005. </li></ul><ul><li>The second public forum was held on March 23, 2006. </li></ul><ul><li>The purpose of tonight’s forum is to present results and conclusions from the Study and solicit feedback. </li></ul>
  3. 3. Study Progress <ul><li>Selection and Evaluation of Final Alternatives </li></ul>
  4. 4. <ul><li>Selection and Evaluation of Final Alternatives </li></ul><ul><li>Evaluation of Potential Benefits </li></ul><ul><li>Study Findings </li></ul>Final Alternatives Jet Analysis
  5. 5. Development of Project Alternatives <ul><li>Development and Evaluation of “Conceptual” Alternatives </li></ul><ul><ul><li>Simplified Modeling of Five Conceptual Alternatives </li></ul></ul><ul><li>Development and Evaluation of “Preliminary” Alternatives </li></ul><ul><ul><li>Refined Modeling Approach (“Upper and Lower Lakes”) </li></ul></ul><ul><ul><li>Six Preliminary Alternatives were Evaluated to Provide Information on a Broad Range of Alternatives </li></ul></ul><ul><li>Three Final Alternatives Incorporating Five of the Preliminary Alternatives </li></ul><ul><ul><li>Similar Preliminary Alternatives Combined as Final Alternatives </li></ul></ul>
  6. 6. Final Alternative 1: Wider/Deeper Culvert <ul><li>Preliminary Alternative 2 </li></ul><ul><li>Existing Culvert Alignment, 2x Width with Invert Set 4.5-ft Below Existing Invert </li></ul><ul><li>Higher High Tides in L NML (+1.5 ft) </li></ul><ul><li>Lower High Tides in L NML (-3.5 ft) </li></ul><ul><li>Increased Tidal Range in L NML (7.0 ft) </li></ul><ul><li>Increased Tidal Range in U NML (3.2 ft) </li></ul><ul><li>29 Acres of Restored Intertidal Habitat </li></ul>
  7. 7. Final Alternative 1
  8. 8. Final Alternative 2: Wider and Deeper Culvert <ul><li>Preliminary Alternatives 4 & 5 </li></ul><ul><li>24-ft Wide Box Culvert, Invert Set 7.5-ft Below Existing Invert </li></ul><ul><li>Higher High Tides in L NML (+2.0 ft) </li></ul><ul><li>Lower High Tides in L NML (-5.9 ft) </li></ul><ul><li>Increased Tidal Range in L NML (10.0 ft) </li></ul><ul><li>Increased Tidal Range in U NML (3.1 ft) </li></ul><ul><li>37 Acres of Restored Intertidal Habitat </li></ul>
  9. 9. Final Alternative 2
  10. 10. Final Alternative 3: Two Larger Culverts or Bridge at New Location <ul><li>Two 24-ft Wide Box Culverts or Bridge with Invert Set 7.5-ft Below Existing Invert </li></ul><ul><li>Higher High Tides (~ +2.6 ft) in L NML </li></ul><ul><li>Lower Low Tides (~ -7.1 ft in LNML) </li></ul><ul><li>Increased Tidal Range in L NML (~11.7 ft) </li></ul><ul><li>Increased Tidal Range in U NML (3.3 ft) </li></ul><ul><li>42 Acres of Restored Intertidal Habitat </li></ul>
  11. 11. Final Alternative 3
  12. 12. Restoration of Intertidal Habitat <ul><li>Potential for Restoration of Intertidal Habitat Increases with: </li></ul><ul><ul><li>Increased Tidal Range </li></ul></ul><ul><ul><li>Lower Low Tides </li></ul></ul>43 12 30 3 38 12 25 2 29 14 15 1 Total UNML LNML Restored Intertidal Area (Acres) Final Alt.
  13. 13. Water Quality <ul><li>Potential for Improved Water Quality Related to Increased Tidal Exchange </li></ul><ul><ul><li>Study Analysis Suggest that a “Jet” will not Propagate into the “Deep Hole” </li></ul></ul><ul><ul><li>Temperature Data Suggests Recirculation of Water Between Lower New Meadows Lake and New Meadows River (“Slug”, as shown in blue ) </li></ul></ul><ul><ul><li>Study Results Suggest that Study Spatial Limits (New Meadows Lake) are Not Sufficient To Evaluate Potential Water Quality Benefits </li></ul></ul>
  14. 14. Water Quality (cont.) <ul><li>Recommendations </li></ul><ul><ul><li>Extend Study Limits Seaward (to Thomas Bay?) </li></ul></ul><ul><ul><li>Obtain Water Temperature Data Within Larger Study Area, Including Vertically-Stratified Measurements </li></ul></ul><ul><ul><li>Obtain Water Temperature Data a Longer Period (i.e., April – October) </li></ul></ul>
  15. 15. <ul><li>All of the Final Alternatives would restore substantial areas of intertidal habitat in Lower New Meadows Lake. </li></ul><ul><li>The potential for restoration of intertidal habitat in Upper Lake is limited by the geometry of the channel under the US Route 1 Bridge. </li></ul><ul><li>In general, increasing tidal exchange in the lake will result in improved water quality. </li></ul><ul><li>The volume of tidal exchange and increased tidal range associated with Final Alternative 3 would provide the best opportunity to prevent the formation of stratified conditions in Lower New Meadows Lake. </li></ul><ul><li>Following on this, there is a high likelihood that water quality would also improve in Upper New Meadows Lake. </li></ul><ul><li>Primary constraints on the implementation of the Final Alternatives include socio-economic factors and cost. </li></ul>Summary of Conclusions
  16. 16. What’s Next? <ul><li>The New Meadows River Watershed Steering Committee will meet next Tuesday to assess and recommend areas for further study. </li></ul><ul><li>Possible topics for study include: </li></ul><ul><li>How might salt marsh habitat & vegetation around the lake respond to implementation? </li></ul><ul><li>How might low lying areas (i.e. wells or septic systems) be impacted by implementation? </li></ul><ul><li>Need for detailed topography & elevation data </li></ul><ul><li>Socio-economic impacts </li></ul><ul><li>Are there additional topics we should study? </li></ul>
  17. 17. <ul><li>Comments/Questions? </li></ul>

×