Let’s follow LPT 21
- Slip and Slide
McKee Clan’s cache
Let’s follow LPT (Little Para Trail) is a series of caches along the trail for you to find. Please enjoy the walk or Ride as we have and happy hunting.
Due to the number of caches in carisbrook park and Howie bowie reserve we decided to start in salisbury and continue out to sea. Enjoy the walk or ride.
FTF – Kyliem34 JFTF – Jamesta18 TTF – Jadedoptimists
Please follow the:
Local point of interest
interest – River Bank Erosion
What causes bank erosion?
Rivers and streams are products of their catchments.They are often referred to as dynamic systems which mean they are in a constant state of change. The factors controlling river and stream formation are complex and interrelated. These factors include the amount and rate of supply of water and sediment into stream systems, catchment geology, and the type and extent of vegetation in the catchment. As these factors change over time, river systems respond by altering their shape, form and/or location. In stable streams the rate of these changes is generally slow and imperceptible.
Rivers are dynamic systems that change over time Stream banks erode for many reasons Stream bank erosion is a natural process that over time has resulted in the formation of the productive floodplains and alluvial terraces common to the middle and lower
reaches of many of Australia’s river systems. Paradoxically, even stable river systems have some eroding banks. However, the rate at which erosion is occurring in stable systems is generally much slower and of a smaller scale than that which occurs in unstable systems. Events like flooding can trigger dramatic and sudden
changes in rivers and streams. However, land use and stream management can also trigger erosion responses. The responses can be complex, often resulting in accelerated rates of erosion and sometimes affecting stability for decades. Over-clearing of catchment and stream bank vegetation, poorly managed sand and
gravel extraction, and stream straightening works are examples of management practices which result in accelerated rates of bank erosion.
Erosion can also be accelerated by factors such as:
• stream bed lowering or infill
• inundation of bank soils followed by rapid drops in flow after flooding
• saturation of banks from off-stream sources
• redirection and acceleration of flow around infrastructure, obstructions, debris or Vegetation within the stream channel
• removal or disturbance of protective vegetation from stream banks as a result of trees falling from banks or through poorly managed stock grazing, clearing or fire
• bank soil characteristics such as poor drainage or seams of readily erodible material within the bank profile
• wave action generated by wind or boat wash;
• excessive or inappropriate sand and gravel extraction
• intense rainfall events (e.g. cyclones).
Processes of stream bank erosion
The various mechanisms of stream bank erosion generally fall into two main groups, bank scour and mass failure. In many cases of bank instability both will be evident, often with either scour or mass failure being dominant. Bank scour is the direct removal of bank materials by the physical action of flowing water and is often dominant in smaller streams and the upper reaches of larger streams and rivers.
Mass failure, which includes bank collapse and slumping, is where large chunks of bank material become unstable and topple into the stream or river in single events. Mass failure is often dominant in the lower reaches of large streams and often occurs in association with scouring of the lower banks. By looking carefully at the processes operating at a site it may be possible to narrow down the probable causes of instability. Correct diagnosis of the underlying causes of erosion problems is important if successful and cost-effective solutions are to be generated. Assistance with identifying the causes of bank erosion and advice on potential solutions is available from the Department of Natural Resources and Water.
Bank scour
Bank scour is the direct removal of bank materials by the physical action of flowing water and the sediment that it carries. Undercutting of the bank toe is a sign of bank scour As flow speed increases, the erosive power of flowing water also increases and scour may occur. Increases in flow speed can be the result of and/or human induced
processes. Undercutting of the bank toe is an obvious sign of scour processes. Effective strategies for combating scour are generally aimed at reducing flow speed through revegetation and in some cases through strategic bank or channel works.
Mass failure
Mass failure describes the various mechanisms of bank erosion that result in sections of the bank sliding or toppling into the stream. Mass failure is sometimes
described as collapse or slumping. Bare and near-vertical banks or areas of slumped bank materials are obvious signs of these processes. The causes of these types of failures are often difficult to determine but can include natural and/or human factors.
Little Para Trail
The Little Para Trails follow the Little Para River, which has many attractions for all to enjoy. Flowing from the City of Salisbury's hilly escarpments to the plains, it meanders through many significant sites that played an important role in the early development of the City. Of great importance are the remnants of natural landscapes present along the river's edge. Varieties of eucalyptus woodland and native golden wattle still exist and some of the earliest almond trees and orange groves are still blossoming.
Points of interest along the trails include Deal Court, Paralowie House, Pitman Park, the Old Water Wheel, Harry Bowey Reserve, and Carisbrooke House.
Little Para River
Origin – near Lower Hermitage
Mouth – Globe Derby Park
Avg Discharge – 3590 m6/year
The Little Para River is a seasonal creek running across the Adelaide plains of South Australia, whose catchment fills reservoirs that supply some of the water needs of Adelaide’s northern suburbs. It runs from its source near Lower Hermitage in the Mount Lofty Ranges, flows north westerly to the Little Para Reservoir and then westerly to the Barker Inlet of the Gulf St Vincent at Globe Derby Park. The lower portion of the river is badly affected by human activity and storm water runoff but the upper reaches have a good range of biodiversity.
The river attracted John Harvey to form his settlement at Salisbury in 1847 and was crucial to the development of the citrus industry from 1852. In the 1960s the City of Salisbury began acquiring land for public space, and a belt of parklands with biking and walking trails now borders the river. The river’s name derives from the Kaurna word Pari which roughly translates as a stream of flowing water.
As the river flows down from the Adelaide Hills over the Para fault escarpment, it has formed a large alluvial fan on which Salisbury is built. The river is narrow and winding, formerly flooded in heavy rain and rarely reaches its sea outlet. Over time the river has been widened and levees added to reduce this flooding. In the 1800s lack of consistent flow in the river and the absence of an organised water supply system led to the digging of wells. The Little Para refreshes the well's water, mostly held in clay, sand and gravel layers up to 200 feet (61 m) deep. The Little Para Reservoir is built in the path of the river for water storage and flood mitigation. As the river's catchment is insufficient to fill the reservoir, it is mainly used to store water pumped from the River Murray. Periodically water is released from the reservoir into the river, enabling refreshing of ground water.
From Wikipedia, the free encyclopedia
For the First to find there is a certificate and a unique FTF path tag. They are not swapped or given out so the first to find pathtag will be a unique item that no one else will have.