Fish Friendly Crossings- Examples from Nash Stream Maggie Machinist- North Regional Forester, Division of Forests and Lands. Nash Stream Nash Stream Forest is 40,000 acres, owned and managed by NH Division of Forests and Lands. It was historically very heavily logged. Log drives were used not only on Nash Stream but the tributaries as well to move wood down to the mill. In 1969, a large wooden dam had a catastrophic failure sending a torrent of water down the valley and destroying the fish habitat in a once productive stream. Hillsborough 1
Failed Dam Restoration Since 2005, NH Fish and Game, Trout Unlimited and NH Forests and Lands has been cooperatively working together to restore the fishery in Nash Stream Forest. Nash Stream is unique in that almost the entire watershed falls within the state forest boundary. Since the beginning of this partnership, we have replaced 6 crossings and permanently pulled 2 crossings. There has also been quite a bit of instream work, including: wood additons, weir construction and boulder placement. Hillsborough 2
Bridge and Culvert Projects Long Mountain Brook culvert replacement Pre-replacement looking upstream September 22, 2008 Post-replacement looking upstream September 29, 2008 Hillsborough 3
Long Mountain Brook Construction This is a flat bottomed, aluminum box culvert. The site needed to be de-watered completely before construction could begin. This type of crossing works well but is very time consuming. There were 1400 bolts that needed to be put in place. The cost of the culvert was approximately $47,000 plus construction costs. Total cost was approximately $85,000. Johnson Brook culvert remediation June 22 24, 2009 Pre-removal Post-removal Hillsborough 4
Johnson Brook This bridge was an ADM bridge. It is a pre-fab bridge that comes with a Professional Engineer (PE) stamp. Assembly is very quick and cost is relatively low. Utilized concrete waste blocks as abutments. Total Cost of the project was $36,000. Johnson Brook culvert remediation June 22 24, 2009 Hillsborough 5
Upper Ferrar Brook culvert remediation The crossing location needed to be relocated during this project. A new section of road was built with a bridge and the old crossing location was put to bed. This was a continuous trouble spot that washed and flooded frequently. The total cost of this project was $28,000. Upper Farrer Brook culvert remediation August 23 24, 2010 Hillsborough 6
Slide Brook culvert May 12 26, 2010 Pre-replacement looking upstream July 20, 2006 Post-replacement looking upstream May 26, 2010 Slide Brook This was the biggest bridge project that we have completed up at Nash Stream. The bridge was 44 long which was replacing a 6 culvert. The slope of the site and the hydraulic capacity of the stream, led to the length of the bridge. Hillsborough 7
Slide Brook This culvert was severely undersized and it was perched. It was impassable to fish. Construction took 2 full weeks. Total Cost of this project was approximately $120,000. Slide Brook culvert remediation May 12 26, 2010 Slide Brook Construction series Hillsborough 8
Construction- cont. Hillsborough 9
Upper Pike Project was to replace an old mill pipe that was creating a large scour hole and undersized. The stream jumped it s bank almost every high flow. The length of this bridge was determined by the angle of the existing road. This bridge was 48 long and on an angle. Total Cost of the project was approximately $70,000 Upper Pike Brook November 1 5, 2011 Hillsborough 10
Upper Pike Brook culvert remediation November 1 5, 2011 Pre-removal looking downstream Post-removal looking downstream Horseshoe Brook culvert replacement May 6 10, 2013 Pre-replacement looking upstream October 2012 Post-replacement looking upstream July 2013 Hillsborough 11
Horseshoe Brook This project entailed replacing a 4 pipe with a 10 9 wide pipe arch culvert. This section of road had blown out several times due to the undersized culvert. It was decided to go with an aluminum culvert instead of steel to lengthen the lifespan of the culvert. Total Cost was approximately $50,000. Horseshoe Brook culvert replacement May 6 10, 2013 Hillsborough 12
Size of Old Culvert Width of New Structure Long Mt. Brook 6 foot culvert 21 2 aluminum box culvert Johnson Brook 4 foot culvert 30 pre-fab bridge Upper Ferrar Brook 2-24 culverts 30 bridge Slide Brook 6 foot culvert 44 bridge Upper Pike Brook 7 foot culvert 48 pre-fab bridge Horseshoe Brook 4 foot culvert 10 9 aluminum pipe arch culvert Culvert Removal Hillsborough 13
Middle Farrer Brook culvert removal November 6 7, 2007 Pre-removal looking upstream Post-removal looking upstream Pre-removal looking downstream Post-removal looking downstream Lower Pike Brook culvert removal November 5, 2008 Pre-removal looking downstream Post-removal looking downstream Pre-removal looking upstream Post-removal looking upstream Hillsborough 14
What to think about as land managers What is this road being used for? Seasonal, Logging vs. Recreation, etc. Engineering costs- Is it necessary? Maintenance costs Can we pull a crossing and utilize a temporary truck bridge when needed? Thank you! Any Questions? Hillsborough 15