The River: The Halfway River begins in Greenfield on the top of Gaspereau Mountain in Kings County. Fed by springs and cold-water tributaries through mixed-wood forests to Hantsport, where it empties into the Avon River. A locally famous trout-fishing stream for many years, the Halfway River remains home to fairly good populations of small Speckled Trout, American Eel, Chub and Sucker.
The Need For Enhancement: Although the Halfway River still provides habitat for resident trout and other aquatics, the capacity of the varied habitats is limited by several factors. Anthropogenic activities over many years have resulted in loss of aquatic habitats, stream-bank alterations, stream-bottom disturbance and alteration or loss of meanders and pools. This river still has the potential to provide top-quality habitat for resident speckled trout. With the intervention of the Wildlife Habitat Advocates and a sound restoration program, this well-known stream can be nursed to better overall health and vitality.
Stream Assessments: In 2004 Advocate volunteers began a stream assessment of the river to determine what problems are now affecting its health. Beginning at a point about 1 km south of the Greenfield cemetery and downstream of the area known locally as The Falls, measurements of the stream were taken and recorded. These measurements included the stream width, depth, pool occurrence and location, location of meanders, stream bottom type, streamside cover type, canopy cover type and percentage, occurrence and type of aquatic insects and stream and air temperatures. It was determined by Department of Fisheries and Oceans Habitat Management technician Darren Hiltz that meanders and pools have been relocated over time and may not be providing optimal habitat for resident trout. The streamside cover is good with a mixture of coniferous and hardwood shrubs and trees which also provide good canopy cover. Stream bottom type has a good mixture of cobble, gravel and boulders, providing spawning habitat for trout as well as cover for aquatic insects. A very good population of Mayflies in all life-stages was evident which suggested that the pH was optimal for trout. Also recorded were Caddis flies, Midges, Water Boatmen, Water Striders and a few Stoneflies. Water temperatures averaged 16C. No fish migration blockages were recorded at this stage. Using a standard formula, Mr. Hiltz determined that pools on this stream should be located every 26 meters. Presently, meander and pool occurrence are irregular and indeterminate and do not follow the natural left/right/left sequence of a healthy and unaltered stream.
Aquatic Species Assessment: On June 2, 2004, the Advocate volunteers assisted Department of Fisheries scientists in an electro fishing survey of the Halfway River and four of its tributaries. These five test sites produced a total of 81 Speckled Trout, 26 White Sucker, 3 Yellow Perch, 19 Chub, and 1 Eel. The total volume of habitat tested was 1,186.19 square meters. The dissolved oxygen (mg/L) ranged from 10.84-11.27, the dissolved oxygen (%) was from 93-105% and the pH ranged from 6.5-7.73. Average stream width was recorded as 18.6875 ranging from 1 meter to 17.5 meters wide. Water depth averaged at 0.96 meters and water velocity measured an average of 2.1 meters per second. The number of Speckled Trout per 100 square meters was 21.26.
Enhancement Prescriptions: It has been concluded by Mr. Hiltz, in accordance with the stream assessments and surveys of this first section of river, that the installation of in-stream devices known as "digger-logs" and "deflector-wings" will be required to help return the stream to a vital, productive and habitat-enhanced environment.
Digger-logs: Digger-logs are in-stream devices used to create pools and meanders by redirecting the force of water. Using hardwood logs approximately 20 cm across at the largest end and long enough to span the stream at the high-water mark of each bank; volunteers anchor the structures at pre-determined locations. Steel rebar of 19 mm is driven through the log, in at least three locations, and into the stream-bed to a depth of approximately 50 cm. Galvanized poultry netting is attached to the bottom of the log to help catch small stones and pebbles, which will aid in water redirection. A stone ramp is then hand-built on the up-stream side of the log, which will guide the stream over the structure. As the water cascades, over the top of the log, it's own force will cause the stream bottom to be excavated, creating a pool in the desired location.
Deflector Wings: Deflector wings are in-stream devices used to re-direct the flow of water and cause a narrowing of the stream channel, which will in turn create a pool, as well as correcting stream-bank erosion and slippage. Deflectors can be made of wood, stone or a combination. Small deflectors use logs secured to the stream bottom and extending out from the bank in a vee shape. The area inside the vee is then filled with large rocks to prevent washout during high-water events such as storms and spring freshets.
Project Mapping and Documentation: All work sites of this project, as well as points of interest and/or possible future problem areas will be plotted using a high-quality GPS unit. All site location information will be stored for future map plotting of the Avon River Watershed. Digital cameras, 35 mm cameras and 8 mm video, will record all aspects and stages of the enhancement project. All assessment and stream survey work will be recorded using standard forms. All measurements, either terrestrial or aquatic, will be in metric. Any and all information regarding this project will be made available to landowners along the river and to anyone requesting it.
Methods of Work: All work will be done using small hand tools including: chain saw, hatchets, hand pruners, shovels,picks, mauls, pry-bars, pulp hooks, timber carriers, timber-jacks, wheelbarrows and a gas-powered auger. In the case of the chain saw, the usual petroleum based chain lube is replaced with vegetable oil to avoid contamination into the water. Refueling is done outside the flood plain over a re-fueling box lined with astro-turf. At the pre-selected sites for digger-logs workers begin by measuring the width of the stream to include the high-water mark of both banks. A hardwood tree of the appropriate length and size is then cut down and trimmed to length. All limbs and cut-off sections of the tree are used to construct ground-cover habitat for small mammals. Using Timber-jacks, workers then carry the log to the installation site and place it across the stream at the desired angle of 35-40 degrees. The locations for re-bar are determined and the log is raised to allow drilling of the holes using the gas auger. After the holes are through the log a piece of ¾" galvanized poultry mesh is stapled to the under-side of the log using 1.5" fence staples. This will help collect small stones and debris, which will effectively create a barrier to water beneath the log. With the poultry wire in place the log is lowered to the stream and pieces of 19 mm steel re-bar is hammered through the holes in the log and deep into the stream-bed. Any protrusion of the re-bar above the log is the bent to prevent catching of debris. Workers then begin building a stone ramp behind the log on the up-stream side. Rocks and stones are removed from the area where the new pool will be created and carefully placed so as to create a ramp on the up-stream side of the digger-log. This ramp will help guide the flow of water over the log and deliver it, in a cascading action, over the top and to the pool creation site. This cascading action causes the stream-bed to be excavated or, dug out, creating a new pool. During the ramp-building process workers will also place very large rocks on either end of the digger-log to help ensure against movement during high-water events.
