Friday, July 29, 2011

Perkiomen Watershed Conservancy's First Rain Garden Takes Shape

Greetings and welcome to the third posting by the PWC about our rain gardening efforts.

If you have been following along, you know that the PWC has been working with local communities to help them meet the Municipal Separate Storm Sewer System (MS4) regulations that have been enacted by the Pennsylvania Department of Environmental Protection. All 50 states are enacting similar regulations aimed at protecting national water resources.

In past posts, we have discussed how important it is to treat our rainwater with a little more respect! Noting that rainwater is the only water available to replenish local ground water supplies. Local water supplies can become stressed as our communities draw more and more water from local wells. So it is vitally important that we give our rainwater a chance to infiltrate into the ground and down to the water table, or aquifer, below. Many older, shallower wells have gone dry as communities have expanded, drilling more wells and stressing localized water supplies.

In addition to our personal water supplies, groundwater supplies water to creeks and streams during periods of low rain fall or drought. As the water table is lowered, streams can loose this water supply from underground seeps and springs, leaving some stream sections high and dry. As streams dry up, the wildlife they harbor either leaves for a better location or simply dies.

These issues would be significant enough to prompt us to take actions to protect our water supplies but it may be even more critical as climate changes continue to impact our region. The Union of Concerned Scientists (UCS) has completed an evaluation of climate issues specific to Pennsylvania.
The report indicates that we can expect more periods of prolonged dry spells puncutated by more severe storms.

Given that we have been struggling through one of the hottest, driest summers on record with rain fall still at about 50% of normal volumes, the UCS's prediction seems eerily accurate. As we all know from experience, once the soils dry out, they become hard and impervious, requiring a long, slow, steady rain that can slowly soak in and loosen dry soils. If we can expect more intense rain storms going forward, it will become more and more important for us to provide areas where rain can be absorbed and allowed to infiltrate deeper into the ground rather than flowing overland directly into local creeks and streams.

Rain gardens are a simple way to provide a path for infiltration of rainwater in the midst of our hardened landscapes. The PWC has received some grant funds from the PADEP to install two rain gardens and a cistern to enhance stormwater management at our headquarters in Schwenksville. Attached are a few photos that show the construction of garden #1 adjacent to our parking lot. You will notice that our garden has no plants in it - yet. That is because the PWC's interns and Conservation Coordinator constructed the garden in 98 degree heat with no rain forecast. So rather than torture our new garden plants, we are waiting for better, wetter conditions.
A composted soil mix was purchased to ensure that infiltration would be possible and to provide better conditions for the new plants.
 The test hole is well-drained! 98 degrees in the shade helps evapo-transpire a lot of water!

 Using the Toro Dingo to remove sod and break up the soil.

It is important that the rain garden be level so that the water does not run through before it has time to infiltrate into the ground.

 Our hardy interns worked in extreme heat to excavate and level the rain garden in preparation for the Rain Garden Workshop held July 20. What a great group of hardworking and dedicated young students! Thank you for your amazing efforts!

 Workshop attendees put the final stones in place for the retaining wall. Plants will be added later once the extreme heat wave ends and rain returns to the Perkiomen Valley.

All finished - for now. The new rain garden will help drain standing water from our driveway and parking lot areas and help infiltrate it into the local groundwater supplies. One small step toward cleaner water and healthier environment.

The PWC rain garden is a large project, certainly larger than most homeowners would need to infiltrate rain from their downspouts.  Our next blog will address how to decide on the size and location of your rain garden.

Please feel free to comment on our blog or contact the PWC if you have questions about stormwater and ways to keep our water supplies clean and abundant. We can be reached at 610.287.9383.