Flood Studies while at Rettew Associates (mainly for bridge replacements):

• Franklin Township, Adams County, PA - bridge demolition and new entrance off of Route 30, over Clear Run
  
• Smithfield Township, Bradford County, PA - Hoblet Road bridge replacement over Tomjack Creek
  
• Big Spring Run Trailhead, Lower Allen Township, Cumberland County, PA - Update to a previous flood study involving a series of two railroad   viaducts and a double 84" x 60" pipe arch under Orchard Street.
  
• Elizabethtown Borough, Lancaster County, PA - new pedestrian bridge over Conoy Creek
  
• Leacock and Paradise Townships, Lancaster County, PA - Osceola Mill Road bridge replacement over Pequea Creek
  
• Manheim/Upper Leacock Townships, Lancaster County , PA -  raise covered bridge on Bridge Road over Conestoga River
  
• Manor Township, Lancaster County, Pa. - two bridge replacements for Rohrer Road over Little Conestoga Creek
  
• West Cocalico Township, Lancaster County, PA - Sportsman Road bridge replacement over  Cocalico Creek
  
• Other minor floodplain related projects/reviews in Cumberland, Lebanon, and Schuylkill Counties, Pennsylvania, and City of Hudson, Ohio.
  

Older:

Disassembly of a covered bridge for County of Lancaster

Rettew Mill covered bridge near Akron, Pennsylvania was located at a tight curve and was frequently hit by cars and trucks. It was replaced by a concrete bridge just upstream. The covered bridge was carefully disassembled and stored for several years until it could be reconstructed in a better location nearby. As part of the project Andy drew a three dimensional model of the bridge (viewable here).

The project involved an Unsteady Flow analysis in HEC-RAS using a combination of eight new cross sections immediately downstream of the dam, plus a 1985 DAMBRK analysis prepared by a previous Engineer. After developing a working Unsteady Flow model, Envalue Engineering was able to satisfy Pa DEP standards, and prepared a report indicating that the inundation zone from the previous Emergency Action Plan was still valid. Pa DEP agreed and on January 5, 2018, granted approval of the Overtopping and Breach Report, satisfying that portion of the Emergency Action Plan update.

Bio-Detention Basin

In 2001, Lancaster County constructed a skateboard park within Lancaster County Central Park. In the same area of the park an existing parking lot and compacted baseball fields created a runoff problem. In order to address the runoff problem and meet Lancaster City storm water runoff requirements, Andy (in his capacity as an Assistant County Engineer) designed a bio-retention basin. The photos shown here depict the changes in the basin over time as native vegetation took over the area, and wildlife began moving in.

Other Recent Projects:

Sometimes the solution to a runoff complaint is as simple as pulling a recycling bin out of the storm pipe it was stuck in.  Unfortunately the solution isn't always as obvious as this, but experience is definitely an asset  when tracking down the source of the problem.

This is also a good example of hydraulics and the power of moving water, even on a small scale.

ONTELAUNEE DAM BREACH ANALYSIS

Ontelaunee Dam in Berks County, Pa. impounds Maiden Creek to form the 1,082 acre Lake Ontelaunee. Envalue Engineering recently worked with Spotts, Stevens, and McCoy (SSM Group) to update the breach analysis for the dam. Also included was determination of the inundation zone for the 3 mile long portion of Maiden Creek located downstream. This project was part of the Emergency Action Plan update for the dam, which must be approved by the Pa. Department of Environmental Protection (Pa DEP).

• Pending: Letter of Map Revision to move floodplain and floodway for Legacy Park, Mechanicsburg Borough, Cumberland County. Flood maps have been revised and will become effective by September 2021.
  
• 2021 - Stormwater management and General NPDES permit for a 50 Lot subdivision in Northampton Borough, Northampton County (Willowbrook Farm Phase 2).
  
• 2020 -  Stormwater management and Individual NPDES permit for a 50 Lot subdivision in Mount Joy Township,  Lancaster County (Westbrooke IV, Phase 1).
  
•  2019 - Pequea Creek, near Paradise, Lancaster County, PA - Continuation of a 2018 flood study for a landscaping business to allow for storage of landscaping stone within the 100-year floodplain. By revising the floodway boundary up to 90 feet closer to Pequea Creek the owner gained additional space needed for a display yard and storage. FEMA approved the requested  Letter of Map Revision (LOMR) in April, 2019 and it became effective in October, 2019. This project also included design of an underground Stormwater Management System within the boundary of the 100 year floodplain.
  
• 2019 - Conewago Creek in Colebrook, Lebanon County - Calculate the Floodway for a 1,300 foot reach of  Conewago Creek, including the Pa. Route 241 bridge. The purpose of this project was to obtain Pennsylvania DEP concurrence that the floodway was not the assumed 50 feet from the top of the bank in locations where FEMA hasn't already designated the floodway.
  
• 2018 - West Branch of Brandywine Creek, Honeybrook Township, Chester County, PA - Calculation of the actual 100-year flood boundary for a 2 mile section of the creek, which is located in an approximate "A" flood zone. Included 24 cross sections and two bridges, plus combination of survey data (within the stream banks) with Lidar contours (beyond the stream banks).
  
• 2018 - Pequea Creek, near Paradise, Lancaster County, PA - Flood study for Township approval of a landscaping business to allow for storage of landscaping stone within the 100-year floodplain and a building pad for a stone cutting building within the 100-year floodplain. The site is located in parts of three Townships. The flood study had to show no (zero) impact from the product storage and building pad  to meet Township requirements. A second part of this project was obtaining a Conditional Letter of Map Revision (CLOMR) from FEMA to allow the building pad to be built within the flood fringe but be considered out of the floodplain for flood insurance purposes.
  
• 2018 - Millers Run, East Hempfield Township, Lancaster County, PA - Approximate 100-year flood study to support two Letters of Map Amendment (LOMA) for two properties along the stream. Required approval by FEMA reviewers.
  
•  2017 - Conestoga River, City of Lancaster, PA - Flood study to determine the possible impact from fill previously placed by City of Lancaster personnel. After FEMA remapped the flood boundaries in 2016 the fill was discovered to be located inside the newly mapped floodplain. The flood study by Envalue Engineering showed no impact on the 100 year flood elevations. Done for the Lancaster City Operations Center, in collaboration with Sanchez and Associates, Inc.
  
• 2017 -Buch Avenue, In Manheim Township, Lancaster County, PA - Basic floodplain delineation for  1500 feet along a small stream, including one bridge at Fruitville Pike.
  
• 2016 - Conoy Creek, Elizabethtown Borough, Lancaster County, PA - Three separate Letters of Map Amendment (LOMA) for three properties along Conoy Creek to remove them from the 100-year floodplain.
  
• 2016 - Columbia Avenue, Lancaster Township, Lancaster County, PA - verified new flood elevations for Little Conestoga Creek using historic (1980) flood study data entered in HEC-RAS.
  
• 2015 - Pool Forge Road, Caernarvon Township, Lancaster County, PA - 100-year flood study for single residential lot.