(Photo along Merced St just E of RM Blvd)Although the storm seemed very significant let me educate you with some stormwater basics. A "design storm" is a storm where (in this area) 2.42 inches of water falls within 1 hour. Thus the stormwater / drainage systems within our subdivison are designed to this standard. As such to see a storm that drops about 0.3-0.6-inches over 1 hour (unsure of exact number here in our subdivision but this was what I was seeing reported in the area) create such major stormwater runoff issues (i.e. erosion damage) is concerning to me and in my professional opinion is due to the lack of the builders in maintaining the proper "during construction" stormwater BMP's (best management practices). See http://cfpub.epa.gov/npdes/stormwater/swppp.cfm for more info. In short SWPPP plans are what the contractor is required to prepare to show the US EPA and Pinal County how they will protect the site during construction when it rains...i.e. how do you keep a land that is partially constructed upon (scarred from grading) from allowing water to wash off the site and move sediment around as erodes the construction property.
I have since moving into Rancho Mirage (almost 2 years ago) voiced comments and concerns because I see the lack of compliance by builders to the typical EPA Stormwater and Pinal County Dust Control regulations. Some months ago I attended a meeting in Pinal County were a representative of EPA Region 9 discussed the new "non-attainment" status of our area due to the continual violations of air quality regulations...also in attendance was the Director of Pinal County Air Quality. As such I quickly sent pictures (taken of the post-Jan storms) and concerns to these speakers related to non-compliance within our subdivision of SWPPP plans...and their contributing to the Air Quality issues. Fairly quickly a gentleman from the County was assigned and asked me questions by email. Following his investigation he provided me with an email update of his findings. I have yet to date heard back from AZDEQ.
I have attached the email feed of the discussion between myself and the Pinal County investigator. See below:
Rancho Mirage - Air Quality Complaint
My concerns / issues with what I am seeing is that due to the erosion of sediments:
- Dirt is in roadways that becomes air entrained and creates air quality issues. This dirt will cause respiratory issues due to high PM2.5 and PM10 violations that are notorious in Maricopa.
- Dirt is being washed and blown into my (and most of our) property and creates more landscape work for myself (i.e. homeowners) and thus costs.
- Dirt is being washed into the lake that can damage pumps and aerators.
- Dirt is being washed into drywells in stormwater retention basins. This will quickly clog the drywells and basins and create long term increases in costs (and potential for damage to our homes) that will be shoulded upon us as homeowners. Not to mention if a true design storm comes and the drywells will not operate efficiently / effectively our homes (properties) could become subject to localized flooding issues.
- Dirt is eroding basins, scuppers, irrigation boxes and thus creates costs due to the need for repair and cleaning of our site.
- Dirt in the roadways is just plain ugly and annoying.
Significant amount of "offsite storm water" had to enter our basin to erode several tons of sediment into our basin. I could see irrigation pipes, drip emitter lines, irrigation boxes all exposed due to the several locations of erosion in this 1 basin on the E side of RM Blvd.
See all the sediment being left. Looks like chocolate soup. The first photo at the top of the post is along Merced is where the stormwater enters the basin along Merced...carrying a significant amount of sediment from bare undeveloped lots into the basins.
Photo above is few hundred feet south from previous photo
Photo above is few hundred feet south from previous photo with RM Blvd in the foreground.
Photo above is same as previous except closer up to see the major sediment erosion.
Photo above is few hundred feet further south of previous picture.
Photo above is few hundred feet further south of previous picture.
Photo above is of the ball fields. There was significant tree damage near the park in the background.
Stormwater carried a lot of sediment into the streets...which then goes into the basins.
Photo above shows stormwater pushing sediment OVER the stormwater control bmp (waddle).
Picture above shows stormwater eroded under the silt fence eroding a signifigant amount of sediment on the street, etc.
Picture above is similar to the previous picture. Across the street is the scupper to the soccer field.
Stormwater BMP (waddle) failed and shows why these controls should be used "in conjunction" with each other and not individually.
Photo above is similar to previous...different view.
Scupper is to the soccer field and suffered severe "undermining" erosion from what appears to be water running through silt fence and along edge of scupper.
Scupper showing why stormwater controls are important. Half worked...Half failed. You can see the sediment is in the failed left side washing into the basin area but being held back in the un-failed area on the right side.
Sediment erosion from unprotected lots
Sediment erosion from unprotected lots
Sediment erosion from unprotected lots
Sediment erosion from unprotected lots
Sediment erosion from unprotected lots
Sediment erosion from unprotected lots
Above photo shows sediment erosion and failed silt fence. Sediment directly enters drainage system as shown.NOW...lets see some "not as bad" photos. I was impressed by the controls placed in the Shea home area on the W side of RM blvd near Honeycutt. You can see this yourself along Olivo and W Vera Cruz. As you will see below there is much less sediment in the roadway which means they are doing something right here. Although there are several locations that the controls need repair. After a long hot summer the silt fence material is becoming very brittle and breaking easy. I do like however the better way the silt fence is anchored using fence posts every 8-12-ft to brace the fence from our high winds.
Above photo shows considerably less "runoff" of sediment in street.
Above photo shows little "runoff" of sediment in street.
Scupper at corner of Olivio and Pratt that empties into "small" lake has good BMP backup when dirt, trash, etc. tries to enter lake.
Reason that I see the better working BMP. The builder actually left a berm to "enclose" the flat part of the graded future home site. This allows 6-8-in of water to "pond" instead of directly running off the site. Thus silt fence only has to handle flow of water from the approximately 20-ft sloped portion of the lot. Water ponding on site is seen in the photo background.
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