Water Ways Presentation


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Water Ways Presentation

  1. 2. Christmas tree tops are pinned down to trap silt on the inner side in flood like conditions. The silt helps form a secondary bank Bank Erosion Works
  2. 3. The trapped silt is then planted up with Willow twigs, which root and help stop any further erosion
  3. 5. Willow Weaving Willow weaving is a very successful and effective way of bank protection
  4. 6. AFTER
  5. 8. Ten foot lengths of Willow are hand weaved around timber posts and then back filled with top soil.
  6. 9. BEFORE
  7. 10. AFTER 4 MONTHS
  8. 12. Willow weaving is normally carried out in the winter months when the willow is dormant.
  9. 13. Normal height of weaving is two feet. Fagots are also used to protect bank erosion. A Fagot is a bundle of Willow which is pinned to the bank of the river.
  10. 14. A plan is first drawn up which shows the new proposed ramp and gradient. Also included, is the positioning of all boulders to be used. Construction of a Rock Ramp
  11. 15. Bridge sills and weirs, can, in low water, become impartial barriers to migrating fish and invertebrates. A rock ramp is a very successful way of overcoming this problem.
  12. 16. The site is first marked out and key boulders are put in place.
  13. 17. This particular bridge sill needs a ramp of 28 meters in length, which will have a rise of 10 millimetres every 3 meters.
  14. 18. Around 400 tonnes of rock from boulders to small gravels were used to construct this ramp.
  15. 19. Boulders are also placed to manipulate the flow of water, which in turn creates kinetic energy, that can be channelled to help migrating fish.
  16. 20. A view of the new rock ramp in a migratory flow.
  17. 22. This rock ramp allows passage of spawning fish in any average daily flow. It takes out any overexertion of spawning fish, that would normally have to overcome a bridge sill in low water. Problems caused by a bridge sill in low water are: loss of eggs due to fish hitting off the concrete, broken skin, which can lead to disease and stress, which in turn effects reproduction and even mortality.
  18. 23. Bridge sill before Rock Ramp
  19. 24. Bridge sill after Rock Ramp
  20. 26. First after careful planning the site is marked out Construction of Fish Pass
  21. 27. Holes are drilled into bedrock, steel bars are then erected to support a concrete wall which will be built to create a deep holding pool.
  22. 28. The concrete is mixed on site by hand, then shuttered, to form the pool holding wall.
  23. 29. The concrete is allowed set for three weeks.
  24. 30. The old mass concrete weir is marked out and lines are then cut out with a diamond blade Con Saw.
  25. 31. A large rock breaker is then brought in to dismantle the reinforced concrete weir.
  26. 32. A lot of steel bars were used in building this old weir, so it took a long time to dismantle.
  27. 33. The old weir was built around 1960, no salmon would have been able to spawn above this spot since then.
  28. 34. (Before Fish Pass) Old concrete weir which is impassable for spawning fish.
  29. 35. (After Fish Pass) Now both Trout and Salmon can easily pass the weir to populate miles of suitable spawning grounds.
  30. 37. Before An area of Glenmorgan Stream which is neglected due to an overgrowth of vegetation and is virtually dammed up.
  31. 38. After The streams now flow evenly and undammed, this allows spawning fish to access miles of suitable habitat thus increasing the numbers of returning fish.
  32. 40. Deflectors Deflectors are formed by encasing small rocks in a wooden shaped triangle. This creates a pool-like effect.
  33. 41. Bank Erosion Work Christmas Trees are pruned along side eroded banks to gather silt, which will create a secondary bank which will be planted up with Willow slips.
  34. 42. River Anner (Before) Stretches of this famous river are so overgrown that no direct sunlight can reach in to the river bed. This has a devastating effect on the food chain, reducing fish stocks to alarming levels.
  35. 43. River Anner (After) By pruning back the bank, vegetation plants such as Ranunculus will return, invertebrates feed on it and fish feed on the invertebrates, thus the natural food chain returns.
  36. 45. Glenary Stream To prevent bank erosion, Willow twigs were planted. They are pruned twice each year to form a Sally Hedge.
  37. 46. The Sally Hedge is very successful as no further erosion has occurred since planting (before this process the farm owner had to move his fencing post 3 feet each year because of erosion).
  38. 47. Instream Habitat Training All participants enrol in a training course which covers the make up and basics of good instream habitat maintenance.
  39. 48. Instream Habitat Training . This course is FETAC accredited and covers subjects like the food chain, photosynthesis, reproduction, migratory habits and the subject of fish and invertebrates and their movements
  40. 49. Proposed Project for 2009 To create a rock ramp fish pass on the river Nire
  41. 50. Proposed Project for 2009 To create a rock ramp fish pass on the river Nire