I also agree with the others who have good experience for the best soil compaction method that is needed for a pond to reliably hold water. Best compaction is critically important. Some dirt movers will skimp on this VERY important part of pond building due to having lack of proper equipment. IMO they try and make do with the equipment they have on hand.
The main reason the weighted scraper is not a good compactor is because it does not knit and intertwine the lift layers together. The scraper smashes the layers however the two layers smashed together as sheets can eventually have seepage develop between those sheets of lifts because the smashed lifts are not well knitted together as one compacted unit. If scrapers were really good at compacting layers of dirt/clay there would not be specialized equipment of sheepsfoot types as soil compactors. Also the mechanical sheepsfoot compactor is the very best because it squeezes water out of the soil so it less likely will allow seepage through it. See more info below.
Think about it. One should use the best tool for the job if you want the best result with the material you are working with. Where this really becomes very important, is ground for building almost all pond basins has a few or several patches or spots where the clay does not have optimum structure and looser soil materials exist. In these areas the soil should be mixed together and these spots are where OPTIMUM compaction becomes VERY important to minimize seepage and leakage in freshly built ponds and then later as pond ages the seepage can work its way between the sheet formed layers created by the Scraper.
I would never use a loaded scraper to build a pond. Way too many chances for leakage spots to occur even when using what looks like all good clay material. It is much cheaper and better to rent the right sheepsfoot compactor than spend time, aggravation and money trying to FIND and fix a pond leak. Just finding the leak site can be a really big challenge. Is it one spot, two spots or several leakage areas? Plus how does one find all those leakage areas???
From construction websites.
Padfoot rollers: Padfoot — or tamping foot — rollers break the bonds between soil particles to compact them better. The tapered feet prevent the soil from fluffing, decreasing its ability to absorb water. Padfoot rollers have large lugs and could either be static or vibratory. The static models are also known as tamping rollers. The drum is covered with bumps that
knead and knit the soil layers together and increases its overall compacting strength. Typically, padfoot rollers are used for clay and other fine-grained soils. They operate at high speeds and can also break large lumps. Padfoots are versatile, typically used to compact cohesive soils like clay and silt. They feature a heavy vibrating steel drum with rectangular or cylindrical knobby pads that pierce and compress the soil, resulting in a compacted surface.
The sheepsfoot roller is most effective for compaction of plastic soils like clay or silt, according to Bomag Americas a leading roller manufacturer. The sheepsfoot compacts from the bottom of each lift towards the top. High contact pressures cause the feet to penetrate through the loose material and actually compact the material directly with the foot tip to reach optimal soil compaction levels.
A number of passes are required with a sheepsfoot roller because of the small area compacted by each foot. Self-propelled embankment compactors, are capable of higher productivity than towed sheepsfoot rollers because they can travel at higher speeds. A tamping foot mechanical roller has feet, or pads, that penetrate the soil, compacting from the bottom to the top for uniform density. The forces of gravity and vibratory impact simultaneously compact from the top down.
Due to the foot shape, and in combination with vibration, these rollers achieve a kneading and impact effect while the imprints left contribute to a reduction of water content.I was always told by a soil scientist that double barrel sheepsfoot is much better at compaction for creating pond liners than single barrel pull behind sheepsfoot rollers
Here is the in depth Soil Compaction Pond & Dam Building thread from the Pond Boss Archives
https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=542647#Post542647
