This tour focuses on places in Lower Paxton and Susquehanna Townships, and the City of Harrisburg. Each stop demonstrates severe impairment, mainly from erosion and sedimentation; the possibilitiy for remediation; and/or an opportunity for enhancement and protection.
Options for taking the Tour:
|1. Headwaters, Patton Road: At the junction of impaired and unimpaired creek branches -- street-wide culverts underneath Patton Road and Blue Hen Ct. Note (1) differences in types of land cover along the two branches: the unimpaired branch drains from forests and fields; this landscape vegetation appears messy, but the organic matter present is effective in absorbing most stormwaters before they reach the stream; the other branch in the area drains from a residential subdivision with runoff mainly from impervious surfaces, 2) the sizes of the culverts for expected stormwater volumes are quite large, attesting to the volumes of stormwaters involved, and|
|(3) The photo at the right shows the relative ineffectiveness of grasses as a buffer to protect streams; the banks of the branch going behind the residential buildings along Patton Road look nibbled along their edges — erosion! — despite grassy lawns extending from the residences to the edges of the stream; grasses are limited at absorbing stormwaters. This site and others are being monitored by the Paxton Creek Rangers of the PCWEA.|
|2. Goose Valley Road:Observe en route the relationship between vegetation and creek condition (i.e., relatively unimpaired reaches exist upstream and downstream of the golf course; only a relatively narrow strip of woodland and shrub vegetation are adjacent to the creek; it is enough to protect from storm runoff associated with new developments in the area.|
|3. Colonial Golf Club: In the distance on the right side the banks of Paxton Creek can be seen cutting across the landscape, parallel with Goose Valley Road. The banks of the stream are eroding and slumping, as the buffer grasses inadequately protect the creek. Golf courses are also known for their nonpoint source pollution, consisting of runoff with products to enhance and protect the golf course landscape (e.g., fertilizers and pesticides).
This photo shows refuse placed in an attempt to stabilize eroded banks of Paxton Creek on Colonial Club golf course.
|4. Winchester Park Retention Pond: Vegetation such as cattails exist in this pond, usually dry, located on the left side behind a high embankment near the entrance to the Winchester Park. Much stormwater runoff flows from impervious surfaces in this development into the retention area, which is surrounded by a fence.
Note that this is a retention basin, not a detention pond where waters can be temporarily stored before discharge into Paxton Creek; although this stormwater alternative does not exacerbate erosion, potential infiltration on site and aquifer replenishment are reduced. On site management of stormwaters from each residence would be much more desirable.
|5. Wooded Floodplain:The creek channel on the right side of the road has eroded to bedrock, and is too deep for most stream overflows except during heavy storm events; in effect, this floodplain is nonfunctional during 95% of the storms.|
|6. The Brook Apartments: Note (1) evidence exists of severe erosion with grass-covered slumps from waters released from underground mall storage; erosion has reached to bedrock, and expanded with increased stormwater volumes, (2) as shown by erosion from side drains, grass is ineffective as a protective buffer, (3) steep slopes are relatively unstable, (4) physical objects such as bridges and pipes are vulnerable to erosion, even leading to collapse of structures downstream, (5) infiltration opportunities were missed, where side culverts extend from lots and buildings directly to the stream, rather than drain into swales before reaching the main ditch, (6) there is an absence of energy dissipaters (large stones) beneath the outlets of culverts, to reduce the force of flowing waters, and (7) remediation would require cutting the embankments to create floodplains, before protective shrub and woodland vegetation could be planted.|
|7. Colonial Park Mall: Note (1) the slight drainage slope on the mall lot, leading towards the southwestern corner, where curbs separate runoff from island vegetation and potential infiltration sites, (2) Prospects for desirable stormwater retrofit could include: removal of curbs, and other barriers between stormwater and infiltration places; soaking strips along the lot perimeter; rainwater gardens and soaking trenches at intervals throughout the lot, with slight pavement humps to direct flows towards rainwater gardens — NOT surface detention basins, or storage tanks underneath the lot (the present approach to stormwater management).|
|8. McIntosh Road Farm: Note the differences as to the stream width, extent of bank erosion, and width of the stream at distances of 50 feet left and right from the bridge. On the left grasses have been planted and mowed to the edge of the stream, where more erosion has occurred (observe the ragged edges and sloping/undercut banks). A small, secondary floodplain area is starting to build in the stream, as deposits in the stream have accumulated near a bank. The whole area is a historical floodplain. It does not serve that function (i.e., water storage), now, following minor storm events, because the stream has eroded so deep that moderate stream levels do not go over the tops of the banks. Due to increased volumes of upstream runoff, the creek has widened because it can not go deeper (bedrock has been reached), further eroding the banks as the larger amounts of water have to be accommodated.
Compare this situation with the reach of the creek on the right side of the bridge. Away from the vicinity of the bridge, the stream is more narrow, and erosion is less evident. Considerable shrubs and trees line the banks, which have a quite messy appearance as compared to the mowed landscape on the other side of the bridge. This fringe vegetation is an ideal buffer, which protects the stream from stormwater runoff into the creek. Once, again, the area exhibits the limited effectiveness of grasses as buffer plantings. A lesson to be learned: messy vegetation is good!
|9. Brandywine Village Detention Basin: Note: immediately before the entrance is a small detention basin, containing cattails and a short riser drain pipe; this pipe discharges stormwaters received from the development behind vegetation another 50 yards alongside Paxton Church Road; inadequate energy dissipaters (boulders, big stones) at the end of the pipe have allowed severe erosion, reaching to bedrock.
Detention basins are the main existing stormwater control technique in the watershed. They can have serious drawbacks, which include the following: worsen erosion through a "fire hose effect" from improperly-placed discharge pipes; allow very little on site infiltration to recharge aquifers, resulting in diminished groundwaters, which worsen supplies to wells and streams during drought periods; habitats become degraded for aquatic wildlife, as sediment clogs creeks, and stream flows diminish and dry up due to inadequate aquifer recharges; detention basins only temporarily store stormwaters, which after their release may join downstream with waters from other detention basins and storage areas, causing larger creek flows with greater erosion, more sedimentation, and even flooding. "Why are detention basins used?" you ask. They allow more impervious surfaces (e.g., roof tops, parking lots, roads and other developments) at specific locations, but create severe problems for neighbors, other parties, and places downstream.
|10. Paxton Church Road, West End: Observe in the distance among the trees on the left, deep erosion cuts into banks and a wider stream, because of aggregated flows from creek branches draining areas upstream. Pins placed in at various levels of an embankment for measuring erosion are present, but they cannot be seen from the road.|
|11. Parking Lot Detention Basin: Erosion exists on the inside slopes of the stormwater detention basin, which receives drainage off the Elmerton Avenue Farm Show shuttle parking area, located above the basin. This 20-acre lot, although constructed in 2001, has no on site infiltration of stormwaters through runoff trenches, swales, or other approaches.|
|12. State Farm Road Curve Vicinity: Note : A lot can be seen at this site. The stream is the Asylum Run part of Paxton Creek. It is a tributary with flashy flows. This means the water levels can vary greatly with storm events, due to rapid runoff upstream from massive amounts of impervious surfaces in Colonial Park, Penbrook, and adjacent areas. (1) The bridge has adequate width and hydraulic capacity for water volume changes; many bridges are too small, with erosion occurring at abutments, (2) access to Capital Area Greenbelt occurs, here. Both upstream and downstream shrubs and trees have been planted on the floodplain, and along the trail by Greenbelt volunteers and HACC students, (3) a Gabion mat (wire container filled with stones) exists along a bank upstream of the bridge; gabions are useful in protecting erosion-prone areas, when installed properly, (4) considerable refuse and debris (even deer carcass remains) have been deposited at this out-of-the-way site by people who are poor environmental stewards, (5) beyond the cable limiting access to vehicles is an abandoned restaurant/club; severe encroachment of the parking area next to the creek has occurred, where erosion is undermining the asphalt surface.
Pins marked by flagging material have been driven into the sides of the embankment at this location for monitoring erosion. (Shown in photo at right. Pins are just below the black box at the edge of the asphalt.) Caution Potentially dangerous situation exists in leaning over the edge to observe the pins. Evident in this area are portals to a major interceptor sewer that runs from suburban townships alongside Asylum Run, a typical pattern for many streams; construction of sewers alongside streams may enhance erosion, by placing unconsolidated soils in the vicinity of flowing waters, (6) a small ribbon floodplain is adjacent to the creek, and (7) drainage from Elmerton Road and the Veterans' Park area enter Paxton Creek through a large culvert, here. This site and others in the watershed are being monitored by Paxton Creek Rangers of the PCWEA. At this location and others are measurement plates affixed to objects alongside the creek; these are staff gauges that show water levels, which are recorded by the stream monitors.
|13. Wildwood Lake Sanctuary: Note (1) the extent of sediment accumulation in this vicinity of Paxton Creek is extreme, as the creek reduces gradient and slows; muck more than six inches deep exists in places on the bottom of the creek, as shown in this photo; 2) the main channel (shown below)
has been blocked with sediment and debris for years, causing a new branch, shown here, to develop, wind its way through woods and wetlands to the base of the upland rise near Olewine Nature Center, and out of the lake south via Morning Glory Drain, and (3) so much sediment and debris has entered the lake that deltas have formed, creating habitat changes (i.e., trees and shrubs on higher grounds), severely restricting water circulation, and nearly separating the lake into lobes. WATER & RESTROOMS are available, here, in the Olewine Nature Center most days between 10 am-4 pm.
|14. Wetlands Strip: This area receives drainage off Farm Show parking lots and roads. Despite flood-prone conditions along this reach of Paxton Creek, especially near the Asylum Run confluence, stormwater retrofit and on site infiltration (e.g., rainwater gardens) are not being practiced in this area, exacerbating flood vulnerability.
Paxton Creek flows in an unlined channel, alongside the Farm Show Complex.
|15. Paxton Creek Corridor Parallel to Cameron Street:Downstream from Wildwood Lake, Paxton Creek is channelized, crossing HACC and Harrisburg, until reaching confluence with the Susquehanna River past the PennDOT building south of I-83, and off Rosebud Island. Observe in the distance, on the south side, channelized Paxton Creek beneath trees (around mile point 20.2), next to impervious surfaces, old buildings, old and new enterprises (Subway Cafe, Appalachian Brewery); these are opportunities for trails and micro-parks — places for potential urban respites, providing relief for urban workers, and enhancing economic redevelopment. The photo shows Paxton Creek in a green, unlined channel near the Subway Cafe at Herr Street.|
|16. Mulberry Street High Bridge:Encroachment Beneath Bridge. Note (1) Paxton Creek is basically a ditch at this point, a straight channel with a concrete liner; these features allow stream flows to travel more quickly away from local areas, reducing vulnerability to floods, but making worse conditions for communities downstream; the concrete liner also affords very poor substrate for aquatic organisms, making Paxton Creek a biological dearth in this portion of the watershed, (2) reinforced high channel walls stabilize the creek banks, but contain no floodplains for water storage, or habitats for aquatic creatures, (3) lateral drainage pipes exist, with some draining fluids which may contribute to the pollution load of Paxton Creek and (4) impervious surfaces, mainly buildings and parking areas encroach upon the stream; the creek has no vegetative buffers to protect it from nonpoint source pollution along much of its urban route. The arches of this old bridge have an aesthetic appeal, which may be enhanced by murals painted onto the bridge in the near future.|
|17. Capital Area Greenbelt Crossing: Access to the Capital Area Greenbelt is here; after securing vehicles, walk along the Greenbelt a short distance to a bridge across Paxton Creek. Note (1) a collapse of the creek's concrete liner is shown, further attesting to the dysfunction of stream liners, (2) portals to sewer mains are located along Paxton Creek is this vicinity; these sewers drain to a pumping station, and nearby wastewater treatment plant for Harrisburg, and (3) beside the creek is a tall stone pillar (abutment?) for the PA Canal, which probably crossed above this site before year 1900. Can you imagine small packet canal boats floating in a trough (bridge) above your head, as would occurred before and during the Civil War? The main Paxton Creek mouth is another half mile downstream, and a ten-minute walk from this point, partially along the Greenbelt.
The Hot Spots Tour ends at this bridge, not at the mouth of Paxton Creek.
If you desire a little refreshment, a little further along the Greenbelt, on the right, is the Lochiel Hotel and Bar, a run- down establishment with unique charm; at this place you can get drinks, simple food, (and hot blues music on Thursday nights); the Lochiel is also reachable via Shanois Street off Cameron.
Lessons learned From The Tour